When one of my family members puts in his username and password and tries to log in, an empty popup window appears. This popup window prevents logging in. Although you can exit out of it, if you try logging in again the same thing would happen.
It just stays there forever unless he presses the X button.
This has been happening for the past 4 months now (started around September).
The app version is 2.413.370504
The iOS version is 12.4.1 (iPad 6th generation).