I'm having the exact same issue with my Fanatec devices. Inputs no longer recognised in AC, R3E, PC2 etc.
All devices and inputs recognised in the Fanatec desktop profiler and Crew Chief etc.
UPDATE.
Have now sorted this issue.
Looks like there was a Steam Beta update issue today. So I opted out of beta participation, (Steam / Settings / Account / Beta Participation (Change)), which rolled back the version and all was good again.
Phew!