I'm going to try to recreate the broken state and send the model to you. I did notice something weird with the folders, so I hide the contents too to be sure. (Sorry for a deleted reply earlier, I thought it fixed by itself while recreating it and it turned out I just deleted a folder and not it's contents 😓)
I've just tried replicating your setup with two empty layers that both have mouse tracking enabled, the inheritance goes like this:
someMoreMotion > someMotion > heart
I couldn't find any issues with this setup.
Did I miss something?
Do all your layers have "hide with parent" turned off?
Yes, "hide with parent" is turned off and I believe that order is correct, but in my case someMoreMotion would probably inherit from another sprite that inherits from aDifferentMotion, etc... So maybe I'm stressing the software too much 😅