I've reached maximum number of testers for my app. That's why I've deleted all testers from TestFlight to clean testers list and invite new and old testers again by public link. But deleted testers are still count in "All testers", but in "Deleted testers" filter. And the error "You’ve added the maximum number of external testers for this app" still occurs. Is this how it's supposed to work or is this a bug?