Sorry, to clarify- My partner and I are both on separate PGWPs, applying for PR together as common-law. We accidentally didn't declare our common-law status on the TRV application based on our individual PGWPs. We have been common law under CRA, so our taxes are correctly filed, but got confused about the 12 month federal requirement vs the 3 year Ontario requirement for common-law when applying for TRV.
I don't fully understand the timeline here, esp the TRV, but I'm guessing it doesn't matter that much. Just write a short letter of explanation that you didn't fully understand etc.
As I understand the basics - as above, there's no automatic ban as for a PR application. And here, if they consider the issue of potential misrepresentation, well, it sounds like you each qualfied as students/PGWPs on your own.
You may want to consult with a lawyer to be sure though.
Note: you've posted in the family sponsorship section, I guess because common law issues come up here a lot. But it's not properly family sponsorship, so you should check in the relevant section.
And caveat lector: I think what I've rwritten is true as far as I know, but I'm just a dog with a keyboard. (Like in that cartoon)