Something super odd is happening to me.
The device is hAP ac2 running 6.46.2. My last successful login was 3 days ago. Since then I didn't do anything.
Now when I try to login via Winbox I am getting a login failure. I thought I messed up the credentials after trying a 100 times but I just decided to do a telnet test and boom!!! it worked with the same credentials.
Via telnet, I even added a new user with a new password and again it doesn't allow me to login via Winbox. I have a feeling this is a bug.
I don't have any filtering enabled for Winbox service.