XCode 11.4 - Reinstalling app in UITest fails: "Could not locate installed application"
It appears to be a bug (or feature) of Xcode 11.4, so that it may not recognise that the app has been deleted if you follow the procedure given in https://stackoverflow.com/a/36168101/13081999 ; in fact others have encountered the same type of problem, and have reported it to Apple, e.g., FB7666257.
I would suggest going back to Xcode 11.3 for now, if you need to delete the test app before each new test. Or manually delete the test app each time.