Whatever IP I use: the Connection test works, settings saved. And then "disconnected" or "not connected". My number of models are discovered. The loaded one not. On next App start my settings is gone.
Am using FF 144.0.2, LM Studio 0.3.31 and testing IP:4567 (not localhost!).
Configured LM Studio to port 1234 and used localhost, then the app could connect.
What's quite disturbing are the limits set by the app. Didn't manage to change the timeout, it stayed 10 sec. The other settings one can change, but I didn't manage to convince the app to remember my values there too. Except the Interface setting. Was saved but not honoured.