Bank mode will not display browser after updates

Running Win 7 and Win 10 in a dual boot system and using Avast Internet Security on both. No problems until I used free update to Avast Premium Security on Win 7. Then, although Bank mode window opens, there is no browser window displayed and clicking on browser icon has no result. Contacted Support and they remotely uninstalled Premium Security and reinstalled 19.8.2393 (build 19.8.4793.531). This also refused to open browser in Bank mode. Booted into Win 10 and updated definitions only on 21/9/19. This produced the same result ie no browser window in Bank Mode. So presumably this fault may not have been caused by the free update to Premium security in Win 7. So far have not updated Win 10 to Premium. Unfortunately, phone contact was lost while the reinstallation was carried out although it did proceed to restart. But fault remains. I expected that having taken my phone number in case contact was lost, the support guy would ring me back but he did not, so I wasted 30 mins assuming he was still working on the problem. Really need to get bank mode working again on both systems so would appreciate any help.

Avast is aware of the issue and is working on a fix.
Many users are affected by this bug.

Post # 39 > https://forum.avast.com/index.php?topic=229461.30