fuel flow between wing tanks

Steve, I had this issue when I first got my plane.
I finally blew out my gas caps vents with compressed air. That did the trick. Must have been a bug or something up in there so it was not properly venting.

I’ve also read that a bad cap gasket can cause a venting problem, as well as having a cap that is way too tight.

Just a question - my coupe is lower on fuel on the R side, every time I gas up. The connecting line was blown out, finding no blockage, last month. Does anyone else have that situation? Do I fly with the left side lower? The tanks are even after we've sat a while. Thanks, Steve