Neophyte having troubles migrating NC to new system on docker

I had NC running on docker on my machine (Ubuntu 18.04) but need to migrate to a new OS (22.04). Everything was running well on docker. I saved everything, and checked my docker-compose.yaml. After using rsync to move all my config files to the new OS, docker-compose stack is generated without error, but opening the WebUI for NC shows: Configuration was not read or initialized correctly, not overwriting /var/www/html/config/config.php

Sorry, but I really do not understand much about this software, so am not really sure how to debug it. In fact, I cannot even find the config.php file where it should be according to my volume mapping. Does anyone know where I should start?