Welcome to the forum. The way I troubleshoot potential leaks in storage compartments is with a bright, 900 lumens, bicycle head light.
I turn on the light, set it in the middle of the compartment, close and lock the compartment, and then look for any light escaping. I wiggle and pull on the door to see if the door moving makes any difference. Waiting until it is dark makes it easier.
I've found bad door seals, and where storage compartments were pulling loose from the motor home wall, using the light test.