The Firmware Hub finds your FM-1 again. AMB-1 1.3.1 (yesterday's) answered the installer in a way the Hub didn't recognise, so it said "No FM-1 found" and you couldn't install another firmware from the Hub. AMB-1 1.3.2 answers it as before. Nothing else has changed.
If you're stuck on 1.3.1 now, this firmware's own install page still finds it: https://charlesvestal.github.io/fm1-amb/install/. Or hold REC while switching the FM-1 on to start update mode, which the Hub finds.
Your pieces' settings carry over.
- Try it in the browser: https://charlesvestal.github.io/fm1-amb/emu/
- Install (Chrome or Edge, FM-1 on USB): https://charlesvestal.github.io/fm1-amb/install/