Remote access just stopped working

That just means it’s not working at all. Plex lists the status as „green“ while checking.

Did you already have a look at the related troubleshooting support article?

https://support.plex.tv/articles/200931138-troubleshooting-remote-access/

There’s also a guide with some more details on how to troubleshoot remote access issu:

https://forums.plex.tv/t/the-basics-of-remote-access-troubleshooting/769517