Checking your logs seems that discourse is not able to connect to Redis. Could you check if Redis is running?
The error seems to be the following:
[ 2019-12-24 08:16:42.8567 2457/7f3593ced700 age/Cor/SecurityUpdateChecker.h:452 ]: Security update check failed: Problem with the SSL CA cert (path? access rights?) while connecting to https://securitycheck.phusionpassenger.com:443/v1/check.json ; this might happen if the nss backend is installed for libcurl instead of GnuTLS or OpenSSL. If the problem persists, you can also try upgrading or reinstalling Passenger (next check in 24 hours)
Could you describe the step you did with your stack before the fail?