Pick Many

A few observations:

1. I'd title the letter choices 1A, 1B, 1C, 2A, 2B, 2C, etc. It makes it easier to troubleshoot and sort variables.
2. The selected state gets that glow effect assigned by default. You have to override it.
3. The submit button has multiple triggers. The submit interaction is allowed to submit if any of the choices are selected. But it's overwritten by the other triggers. I suspect that's where the issue lies because you are submitting it if "or" is met which is always the case.
4. I'd create a T/F variable to track each question. Change to True is any of 1A, 1B, or 1C is selected. 
5. Submit interaction when 1-6 are all True. This doesn't require all of those conditions and works. See slide 2.