Restored from backup, got this. It shows v0.0.0 instead of 0.12.3.
Nginx Proxy Manager 2.1.0 is available. You are running 0.12.3.
Hmm maybe that's part of the issue.
After restoring from backup, Nginx didn't autostart so I had to log into HA via the local IP and kick it off. As soon as it started, all my reverse proxy URLs began working. Despite working, I cannot login because my user account has been reset I'm guessing.