Without seeing you shoot....lets run down some possibilities.
If your fingers are not getting sore I doubt the tab is too small so,the powder marking the tab all the way to the edge indicates, your not getting off the string cleanly, perhaps relaxing a bit at release and the fingers are getting scrubbed...use those back muscles and pull harder!
There's another possibility I've seen before, in the case of not enough back tension or loss of back tension at release....it may be your finger uncurling that's hitting your lip or perhaps a fingernail??? Use tape over the ends of your fingers to check for sure.
You mention this only started with a different bow? Check how your gripping the bow....bow hand torque can cause increased string oscillation and of course the string rolls off the fingers headed left(RH shooter)so any increase in string oscillation can can cause the string to catch skin or in some cases its the arrow nock that hits you while still on the string...nock indexers get me from time to time.
BTW is the new bow a different draw weight? With heavier bows , guys tend to turn the head into the string in an effort to help out handling the additional draw weight.
Lighter draw weight bows, don't create as much forward string energy and issues such as bow hand torque and not getting off the string cleanly are often maximized.
Geeesh...its lots easier solving problems, when you can see a guy shoot a few shots. :D