Unable to connect to HA via any browser or app locally or externally

I have been using HA for months in the same setup with no issues. I setup port forwarding and duckDNS ages ago and when doing so, lost the ability to connect via the IP when local. So I always connected via duckDNS when local instead as that worked fine.

However a few days ago I can now only get the:
Unable to connect to Home Assistant screen with the HA logo both from web browser and companion app. The raspberry pi running HA still flashes green when connected via LAN cable (which I have tried in multiple ports) but that hasn’t changed anything.

I am unable to access HA so I can’t install NGINX or other solutions outlined in other posts, nor can I post logs because of it. I have snapshots but only on the pi’s sdcard so I have been hoping to avoid reinstalling HA from scratch without being able to access the backups. My google home won’t connect to HA anymore, but I didn’t leave any automations on when this occurred (I was away for a few days) so I can’t check those.

Any help would be appreciated please.

You could try

https://ip_of_HA:8123

And accept the invalid certificate.

I’ve tried this but just get a connection refused error.