Unclear GPA + SA offer

Hi everybody, I'm studying in a country (at a top target) where the "undergrad/grad" system is very different from the US/UK.

So what's happening is that British HR don't understand anything, and I basically manage to get SA interviews while putting some vague non-sense instead of actual GPA (which is bad if you compute it as you would in a US / UK uni)

So here is my question, I have a few ACs scheduled and i hope to land an offer.

And I was wondering, could the offer be withdrawn because of the GPA thing ?

I didn't lie technically. I just put stupid non-sense stuff instead of the "GPA", and since UK HR are note confortable with it they usually don't throw it to the bin automatically so I'm getting interviews.

What will happen is basically this : Offer (I hope) ===> accept ===> Background check ===> "lol wtf is this stuff ???" ===> Transcripts with random grades ===> ?????!!

Thanks for your opinion on this.