Yes. Agree bacteria produces gas. But the eggs don't smell. I discounted bacterial build up as it always comes with the bad sulfur smell. OP stated no smell.
Weird. I've gathered eggs and broody hatched eggs and never had one explode except an obviously bad smelling one.
Just my experience.
LofMc
What are your temperatures? I can't think of a single disease that would cause a gaseous build up in the egg that would cause it to explode. Even thin shelled eggs don't explode. They just crack and disintegrate.
My only, only thought is that your temps are high outside, and somehow bringing...