I'm in a pickle. Lately I notice that when I put my fondant over my iced cake, and even after I smooth it out with my smoother all around, in a few hours I notice a bulge on the sides of my cake horizontally where my buttercream is in between the layers. I do everyone to tighten the gap when I ice with buttercream to make sure there is no gaps or air escaping. But somehow I still end up with a bulge and it's just not as smooth as I would like it.
Can anyone help me figure this out? Would appreciate it so much.