Expanding body pieces on Electric

I've had several guitars show signs of the body pieces expanding, quite unevenly.

I have one guitar with at least a 3 piece mahogany body, starting to look like the middle piece has grown larger than the side slabs and it's affecting the top finish because it's now protruding by the seams. It's uneven and the top profile is no longer straight. You can feel it to the touch but it's hard to photograph.

I've sent them to luthiers and they just told me it's normal (I live in a tropical climate area), but what I wanna know is how do I prevent this from happening? I don't notice this in other people's guitars and if I ever get a really nice one I don't want it to spoil the finish. It's too noticable to me. It's caused cracks in the hardware too, like the pickup rings.

I've tried leaving the guitars in their case with silica gels in fear it's a high humidity issue but they still warp.

Anything else I could try or anybody else go through the same thing? It's hard to find info on this specific issue online or at least a name for it.