Some users make the mistake of also deselecting DMX universes when changing a layer filter.
I suggest to make it clearer putting a line in the filters dividing layers and universes.
An item cannot be in more than one layer at the same time. So the assumption with filters is that an item can be filtered only once. In the case of filtering on Layers and Universes this seems to be a bit blurred. I've made the mistake as well. I am not sure how, but a bit of clarification could certainly work.
Hey Florian, I mean something like this: