I have such trouble stacking cakes with any type of fruit filling. I always start with even layers, a super stiff dam, and a very thin coat of fruit sleeve filling but somehow they always shift. I also leave them to settle overnight. What am I doing wrong?
For an example, see Damask wedding cake in my photos.
That is a beautiful cake. Your stenciling is gorgeous.
It sounds to me like you are still using too much filling. I describe my fruit fillings as a 'smear'. If you can't see the cake thru your filling, then it's too thick.
Do you spread a thin layer of buttercream over the cake before spreading on the filling? If so, quit doing that. I know of several people whose sliding problem was caused by that.
Lastly, is your dam higher than your filling or level with your filling? The dam should be higher than the filling so when you press the cake layers together, it forms a seal around the filling.
Good luck! Hope you find your solution soon!