Sorry about that
I found this in a payware B737
This is in the Aircraft.cfg file in the Autopilot section
This could be what triggers it.
but I am not sure it might be part of the model file I have not been able to find anything so far as to what triggers this warning.
I also discovered that the bank angel warning is part of the Ground Proximity warning system in this aircraft
I found this video that might help https://www.youtube.com/watch?v=R-4Q8mhpFLU
This aircraft is very similar to what I have THE PMDG 737-800 NGX & PMDG 737-900 NGX
it has the exact same system and the panel appears to be identical to my panel