Hi Michiel,
For the error.log files, I can see some errors relates to a theme but it points inside the /bitnami/wordpress/...
folder in /opt/bitnami/wordpress/...
2022/05/27 14:28:33 [error] 17857#17857: *26427 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 218.53.233.146, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:28:34 [error] 17857#17857: *26427 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 218.53.233.146, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:32:50 [error] 17857#17857: *26463 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 193.106.191.48, server: _, request: "GET /vendor/phpunit/phpunit/src/Util/PHP/eval-stdin.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C:80"
2022/05/27 14:34:12 [error] 17857#17857: *26477 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 219.249.26.201, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:34:12 [error] 17857#17857: *26477 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 219.249.26.201, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:37:56 [error] 17857#17857: *26500 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 177.92.247.70, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:38:01 [error] 17857#17857: *26500 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 177.92.247.70, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:45:55 [error] 17857#17857: *26575 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 59.5.23.206, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:45:56 [error] 17857#17857: *26575 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 59.5.23.206, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:47:34 [error] 17857#17857: *26594 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 46.136.146.128, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:47:34 [error] 17857#17857: *26594 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 46.136.146.128, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:48:36 [crit] 17857#17857: *26601 SSL_do_handshake() failed (SSL: error:14201044:SSL routines:tls_choose_sigalg:internal error) while SSL handshaking, client: 162.216.19.41, server: 0.0.0.0:443
2022/05/27 14:51:14 [error] 17857#17857: *26614 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 39.117.229.108, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:51:15 [error] 17857#17857: *26614 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 39.117.229.108, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:53:41 [error] 17857#17857: *26639 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 80.94.93.250, server: _, request: "GET /admin/config.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 14:55:49 [error] 17857#17857: *26661 FastCGI sent in stderr: "PHP message: PHP Warning: Unknown: failed to open stream: No such file or directory in Unknown on line 0Unable to open primary script: /opt/bitnami/wordpress/index.php (No such file or directory)" while reading response header from upstream, client: 172.70.246.33, server: _, request: "GET /602048/402799144/bs8cce37Wwhute6ff8cco2.htm HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "host-domain.com"
2022/05/27 15:05:23 [error] 17857#17857: *26715 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 1.244.182.22, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:05:24 [error] 17857#17857: *26715 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 1.244.182.22, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:19:58 [error] 17857#17857: *26809 access forbidden by rule, client: 95.214.235.205, server: _, request: "GET /.env HTTP/1.1", host: "X.Y.Z.C"
2022/05/27 15:24:25 [error] 17857#17857: *28334 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 46.71.28.241, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:24:25 [error] 17857#17857: *28334 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 46.71.28.241, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:26:26 [error] 17857#17857: *29636 access forbidden by rule, client: 135.125.246.110, server: _, request: "GET /.env HTTP/1.1", host: "X.Y.Z.C"
2022/05/27 15:27:21 [error] 17857#17857: *29887 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 61.85.74.23, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:27:21 [error] 17857#17857: *29887 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 61.85.74.23, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:31:07 [error] 17857#17857: *33617 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 43.152.199.49, server: _, request: "GET /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:31:12 [error] 17857#17857: *33617 FastCGI sent in stderr: "PHP message: PHP Notice: Undefined variable: gM5598 in /bitnami/wordpress/wp-content/themes/L6UL67AE/D7BXK114.php on line 1" while reading response header from upstream, client: 43.152.199.49, server: _, request: "POST /wp-content/themes/L6UL67AE/D7BXK114.php HTTP/1.1", upstream: "fastcgi://unix:/opt/bitnami/php/var/run/www.sock:", host: "X.Y.Z.C"
2022/05/27 15:33:52 [crit] 17857#17857: *34026 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 178.73.215.171, server: 0.0.0.0:443
Regarding the max_children value via the link you provided, it was not present in the file /opt/bitnami/php/etc/php.ini
so I added it. Still the same issue, wp-admin page not accessible, wp-login appears but can’t log in. Our collaborator also see the ERR_TOO_MANY_REDIRECTS
I ran the bndiagnostic diagnostic tool and this is the code 32dd6221-5d94-a989-6fa6-4f56ac953501.
Thank you