What version? Are you still on 12.1.05?
Your last paragraph about the required field even though it's not on form makes me think of an issue with 20.20.01.. I don't think BMC has acknowledged it as a defect because it's a pain in the butt to reproduce, there were a few posts on communities about it but cant find it right quick. Essentially it seems the fix is in each item, save the business rule page, then publish.
We're on 20.20.01 now!