Why does sink gurgle after installing AAVs in attic?
There is a blockage downstream of the kitchen. AAV allow air to enter the system and not exit. Plumbing systems are a neutral pressure system and the vent equalizes the pressure on the back side of the waste water. As the water from your laundry goes down the drain the blockage causes a pressure build up that the AAV no longer allows to escape. Removing the AAV allows the air to escape up the vent pipe.

One other possibility is a main waste line trap with the vent removed.

Main waste cleanout



Chest of Books

Some houses still have a set up like this. In this picture the vent is on your lawn and the clean-out is under the sidewalk or street. Often people remove the vent because it looks like some weird piece of metal with a cap on it sticking out of the lawn. With that vent gone and AAVs added top the air has nowhere to escape. This is an unlikely scenario but it is possible.