Please help- OCR History A-level- I think I've been given the wrong grade?

I did OCR History A at A-level. I did my coursework and I got 37/40 which is an A*, but today have received it back as 30/40. I wasn't made aware that my coursework grade could change that much, but I'm sure there is something wrong as everyone else on my course has also had there marks significantly reduced. Because of this, I missed out on my A grade in History, and to be quite honest, I'm distraught.
It seems odd because it was marked by three teachers and they've never had coursework come back with such drastic changes to the marks originally awarded.

Did anyone take this course and find the same thing?

Have you spoken to your exams officer at school? Are they going to ask for remarks? If not, you could still apply for a remark.

Do you need your A grade to achieve your uni offer?

I managed to talk to my teacher and I think she's going to arrange for the whole year to have a remark on coursework as this has never happened before. I still got into my firm Uni, but I feel like it's wrong for all of our coursework's to be lowered that much, especially if they've had no problems with their coursework marking in previous years. Is it normal for coursework to drop by this many marks? I would have understood if it had just dropped a couple!

It's not usual, no. Have you school changed exam boards or anything like that?

As you've got into your firm, I'd try not to worry about it too much, but I can see why it is annoying.

No, we're with our usual exam board and there's never been problems like this before with coursework. Grade boundaries this year stayed the same as last year too. It makes me think that somehow we've been sabotaged...

It's just really disappointing because I thought I had secured that grade, but clearly not. I'm really grateful that I still got into my firm, but I'm doing Ancient History and Archaeology so an A would have been useful, especially since I worked so damn hard on it!!

Thank you for replying