Hello @j0chn, welcome to the Nextcloud community! 
your setup looks pretty complex so I didnt follow in depth. I would recommend you start with a simple setup and extend once you now it works well - my very basic checklist is major upgrade, backup and restore, test from desktop and mobile.
Please look at How to docker-compose with notify_push (2024) for working advanced example.
as I didn’t find a way to integrate existing setup into portainer and some other portainer limitations I never adopted the tool so no idea in this terms - but you definitely must avoid auto-updating of NC and postgres - sooner than later you are in trouble.