Filter by Universe appears to be a special type of filter. It acts as an AND filter. 

Example:

I have a fixture in a layer (Layer 1) and patched to a Universe (Universe 1).

I set a filter to include Layer 2, the view with that filter applied does not show the fixture from layer 1. This is expected behaviour.

If I have two fixtures in Layer 1 and one of them is patched in Universe 1 and the other in Universe 2 and I check the filters to include Layer 1 and Universe 1 (and uncheck the others), one of the two fixtures disappears from my view. Also expected.

But in the same situation I uncheck the filter for Layer 1 (so no layer filters are selected) and only the filter for universe 1 is checked, no fixture is shown in the view.

This makes filtering by Universe impossible. Is this correct behaviour? Is there anything wrong with setting the universe filters to the same mode as the others? Because now I can filter to see my layers 1, 2 and 4 from only universe 1, but I cannot show all fixtures in Universe 1 regardless of which layers they appear in.