I'm experiencing two problems while using Excel in my Windows 11 VM

1. I'm using Parallels 19.4 (please don't suggest I update to 19.4.1) under macOS 14.5. While creating new VBA content in Excel, the characters I intend to enter just once are often entered twice. This also happens when I backspace which can cause serious problems; If I select a line of code and then backspace, it may also delete the line of code above the one I intended to delete without my noticing it. I would blame it on my Apple Magic Keyboard, but the problem doesn't happen outside my VM.
2. Recently I went to Apple System Setting->Displays and changed from the second from the left built-in display option to the "Default" option which caused everything in my Excel window to flicker wildly. Waiting didn't help and it was difficult to stop it manually.