same issue here.

same issue here in the VisionOS simulator.

I had encountered the same problem. After some time researched and I found out the reason. Apple had changed the private function [_UIRemoteKeyboards peekApplicationEvent:] 's implementation of UIKit in iOS14.2. the touch event of custom window will call [_UIRemoteKeyboards peekApplicationEvent:] function. in previous version [_UIRemoteKeyboards peekApplicationEvent:] did't call [UIWindow _makeKeyWindowIgnoringOldKeyWindow:] to change the keyWindow. but in iOS 14.2 [_UIRemoteKeyboards peekApplicationEvent:] did. so it's the reason why the keyWindow change when you touch the custom Window.