Can you be more precise in the exact problem you're having with Bank Mode?
I open Security and Privacy Center in Avast Secure Browser. I click on the button to open bank mode. The button seems responsive, but bank mode won't load. I will try later and give it more time, but the normal gray screen doesn't even show.
Also I note that in task manager of the Win10 computer there are 3 Avast services that are stopped. I don't know if the update was responsible for stopping those. I assume I would need to start those through startup.