Hope you are doing well. Sorry for your experience with Adobe Scan.
Were you trying to log in with Facebook? There was a bug from Facebook which was preventing the sign-in to applications using Social platforms.
Would you mind letting us know if you still experience the issue with login? If yes, please share a screen recording of the issue for us to investigate further.
Yes, I am still facing the same issue while signing in Adobe scan through FB and Gmail. Fix the problem immediately. Hope you will fix it quickly and let me know about it.