NextCloudPi - Ports are closing spontaneously

I managed to set up a NextCloudPi server using my RPI4, and connect it to the home network and also to a DDNS quite easily. Works like a charm.

But then for the last week, I’ve been having a recurring issue where the ports on my NextCloudPi server are closing spontaneously. This happens every day, or every other day, and it’s quite annoying to have to log in to the TUI or WebUI and re-run the port forwarding to re-enable them.

Is this a bug I should report, or is there some configuration I’m missing?

Port forwarding is a NAT function normally done on a firewall, but you seem to be saying you’re doing port forwarding on Nextcloud itself? Please explain.