That’s probably why.
- Sign out the plex/web browser
- Open a new Window
- Go to to www.plex.tv (not app.plex.tv)
- Sign into your account settings.
- Force sign out everything as you change the password.
- Open an incognito window
- Open http://ip.addr.of.host:32400/web (or 127.0.0.1:32400/web if on the host)
- Sign in
- Claim it again.
The X-Plex-Token and other credentials will now all resync
go to your devices and sign them in again.