Airpods pro automatically adjusting bass

I just recently upgraded from second gen airpods to the airpods pro and almost immediately noticed the lacking bass, and then turned on the bass boosting feature (which didn't do much, we need a custom eq graph). One thing I noticed was that if I took out my airpods just so that they were out of my ears but not enough to pause the music and then quick put them back in my ears then the bass was much stronger, more like the 1st and second gen airpods and what I like. Then after a second or two, the bass tapers off to what it normally is. I find this really odd seeing as I had both noise canceling and transparency mode off while testing this and that means that there isn't a mic on that is adjusting the audio in your ears. Anyone have any idea as to why this is happening?