My userforms intermittenly lose focus and disappear when performing tasks on worksheets

Hi, your suggestion was working fine but, Microsoft sent a windows update in the last week and my main userform is now doing very strange things, it's almost like it has 2 copies of the form open, clicking the exit button doesn't close the form, keeps focus, then the form closes on the second click. I've started building a replacement userform which runs some code that takes a while to complete. Intermittently, there is a white band that flashes across the top of the screen, too fast for me to catch what it says. I used xbox gamebar to try to record the message but it didn't show the userform or the error message, although they both happened. Now, do you happen to know a command that I can embed into my code to make it look like excel is still running?