There is a bug in v. 7.3.1. If you are off line and touch "Premium Not Purchased" in Settings, you get a window which says, "Cannot Purchase Subscriptions." When that window comes up it locks the settings window and no changes can be made to settings. If you click "OK" in that notice window, Settings quits. Quitting and re-starting the app does not correct this. Shutting down the iPad and restarting does not correct it either. This is with iOS 16.6.1. The only way to get out of this is to have a wifi connection. But this is not always possible when observing from a remote site, thus no settings can be changed until a wifi connection is made. When you're miles away from a connection at a remote site this can render the app useless.
[UX Issue]* SS7 Basics Inaccessible