Although not explicitly Android security, it’s personal security. There is a whole section dedicated to this in your phone.

Restarting is always a good fallback, but before you get to that point, there are other steps you can take if you're off the grid and disconnected.

T-Mobile's self-service SIM managing tool is back in the T-Life app. Here's how to get it set up and transfer your own SIM cards and eSIMs on your own.