Can't answer calls when screen is locked
The setup of my GSM sim seemed to go fine. Using the app, I can make and receive calls. Texts are working fine. The only issue I've run into is that when the phone's screen is locked, calling the phone results in a single ring and a very short lived display of the phone app that goes away too quickly to be able to swipe and answer the phone.
While the call is still coming in, unlocking the phone still does not bring the phone app back and the call can't be answered.
Any idea what setting needs to be changed