I’ve had this issue. I know I didn’t let my cake sit overnight and relax after crumb coating. I do now, that way if a bulge appears, it can be fixed before I apply my fondant. Also, you could be correct that your 2nd tier cake was to heavy for the lighter cake on the bottom. But if you doweled, and ganached, and it settled, should have been fine. How many dowels did you use??
Perhaps others here will weigh in with some good sage advice….
Creativity is God's gift to us. Using our creativity is our gift back to God. Clarky's Cakes 😎
