An aav would possibly stop the gurgleing . I doubt very much that its unvented but anything is possible .
I still suspect a stoppage .
I ran a snake down and there was no stoppage. I was able to get a look behind the cabinet and the two trap arms feed into a 90 elbow, before it drops down to another 90 and continue the run and connect with the other 1 1/2" pipe.
I don't see any other pipe coming In horizontally.
When I loosened the p trap slip joint nut, I could hear air hissing - there was still water in the p trap.
I guess the next course of action would be to add an AAV?
I suspect since this kitchen got renovated, whoever plumbed it, didn't go a good job.