Same problem here. I also pay for premium and am getting password filled in username. And worse, it is showing the password characters instead of hiding them as it would in the password field. For me this is with my local credit union app and some others as well.
So far I've seen several people have this problem but no solutions provided in 10 months. Please advise ASAP.
P.S. If it makes a difference, this is on an Android phone for me.
The user and password are now being entered in the proper fields in my credit union app. I do have inline autofill enabled so that is probably what fixed it, but I honestly don't know when it started working because I pretty much stopped using the phone app unless I had no other choice (LastPass at the time was making it so hard to log in) Anyway, thank you! And I hope this works for others in other similar apps.