Whenever I try to login to Battle net it tells to enter my password, NOT that my password is wrong, and I know the password is right. It does this for any account I use to. I can login to Overwatch and the mobile app just fine. It’s been happening since just before WoW Classic came out and I assumed it was just related but it’s still doing it.
Same issue have you found a resolution by chance? A blue post would be nice, guess it’s time to write another ticket… I tried to reinstall and the issue persists. I even changed to to the beta Battle .net App and nothing. I copy in the password so I know it’s correct. I can log in on other computer’s just fine and I can play WoW on this PC if I bypass the login to the app by continuing offline. Or, by opening the .exe directly and typing the password in there. Though it’s still kind of annoying how after all this time it’s still a thing.
Lets go ahead and try reinstalling the app as described on this page. Let us know if this works for you!