On iPhone 16e running April '25 (pre 9) Release 25.3.99-pre9 - Base Build 25.3.100
When I go to Settings then go to enter the operator callsign the screen briefly comes
up to enter (or change) your callsign, then disappears and then the app locks up.
If I switch out of the app and pack into it the callsign field is there and callsign can be entered or modified.
This error does not occur on my iPad.