If I recall correctly, if you're using global layers you should make sure that your layers are named consistently across all layouts and that they use the same hierarchy eg if ItemStore layer is layer 3 on Level 1, then it should also be called ItemStore on layout PP and also be on layer 3. If you don't have that layer set up in other layouts with the same name and hierarchy it won't work as intended. Hope that makes sense.
So if I understand correctly, whatever layers I have or will have throughout my multi level game, I will need to that in my global. Is that correct? I have a level named Start in my first layout called PP. I don't need that layer in Level one, but will it need to show up there as well as in the global layout? Thanks.