Just installed Avast Ultimate - could not login to my online banking. Tech support insisted it had nothing to do with Avast, despite the many similar forum complaints. I uninstalled Anti-Track - my banking now works. Go figure lol.
Whilst I don’t use the Anti-Track product, so I can’t speak from personal experience.
I don’t know if the way that anti-track works isn’t in conflict with you banks security and it is blocking. This could prevent the logon. I don’t know if you added your banks URL to the exceptions either in Anti-track or in Avast Ultimate so neither operate on your Banks URL.
So if this is conflict, removing one part of that conflict, if it works it would like Avast was the problem.
Ordinarily I would expected Avast to Alert or for the Anti-Track to comment or notify.