Hi @orubinx, you mentioned using Bitnami WordPress stack, not WordPress Production-Ready, just mentioning this to avoid confusions and because these are two different Bitnami products.
As for your WordPress HTTP 500 error issue, it is most likely related to either the PHP-FPM proxy working slow or the MySQL server not having enough capacity. It is most likely the second one as for these issues in the MySQL log file:
2019-08-11T08:31:41.993226Z 0 [System] [MY-010229] [Server] Starting crash recovery...
2019-08-11T08:31:42.006879Z 0 [System] [MY-010232] [Server] Crash recovery finished.
In order to confirm this, when your server is experiencing HTTP 500 errors please run run the commands in this guide:
Please share the results of those commands.
In addition to that, please ensure you're not getting attacked by bots by following this guide to identify them (and block them):