So I’m busy editing and work packages. Every few minutes (1-5 minutes) something happens and the app stops working.

I refresh the browser and have to log back in?

How do I troubleshoot what is happening under the hood?

Check the apache logs $APACHE_HOME/apache2/logs/ if nothing there check the passenger logs.
Also what was recommended on the installation. /home/openproject/openproject-ce/log/production.log