Another possibility besides the tab...but relates to the tab:
We were taught in FITA competition to completely relax the fingers upon release. Many people struggle with fully relaxing, and when the string breaks free of your grip, you still have tension and the fingers/tab/glove come back and slap you.
If this is the problem, shoot in front of some bales or whatever nice and close. You dont care about accuracy, just form. draw on the bale/target, dont really pick a spot but anchor and hold it, then just concentrate on complete relax of the fingers when releasing, some guys literally pointed their index finger at the target as a method and all other fingers followed.
If your fingers are indeed slapping you, it is not good for follow through for anyone, it creates an involentary tensing when your fingers hit you, and all kinds of issues can arrise from handle torque to losing back tension.
At close range you dont notice the effect as much, but at 90 meters..it can be three feet off.
String walking adds another variable to the mix, which is fine! But if your release insnt good, string walking will make you suffer worse. Your release is more critical for you than most doing that...so make sure it is top notch!