How to catch a crash with no exception or errors?

Hello everyone.
Our game was crashing 2 seconds aprox after start. The crash was without any exception, just crash and out the game.
We plugged the device (iPhone 8 Plus) to Xcode , 1.2GB / 2GB Ram were being used when crash happened. And Xcode log didnt show any exception or error. Simply displayed "The device was disconnected" when the crash happened.

The weirdest thing is after this test on Xcode, it didn't happen anymore. But I'm concerned If this were to happen again... how to detect where is the problem?

Thanks a lot.
pistoleta