When the groups are released into layers I have to specifically deselect any object that I have selected in that layer. If not and I want to simply select the next group or object to continue the same procedure, that layer which I have just released and has an item selected will keep popping open even if I close it specifically. Every time I click on a different object or group in the layers panel that last released one will open up, and in my case it contains a looooot of objects.

Also, as mentioned before, sometimes it seems not to release everything for me as well, just randomly leaves one or two groups if I decide to release everything in the layer I'm working on.