So for some reason everyone time i attempt to do a submission against the CPU no matter how low their stamina is they still break it. Is there any reason for this or is the CPU just like really fucking hard to make submit.

Fucking Gamesharks.

Depends on a variety of factors, your fighters submission offense, the CPU fighters submission D, both fighters power ratings, if you're just jamming on the buttons or doing The Shine, what difficulty level you have it on, both fighters stamina, etc.

Remember, it's not just one button you can hammer on, hammer on all four like a typewriter.

The CPU is just a real pain to submit, Although the one tip I have is that if you are button mashing I find spinning the right stick to be more effective.

are they ever going  to make it so you can only use the stick? Allowing players to button mash with the amount of modded controllers out there was fucking idiotic.