Answer by David Dickinson:
First, good catch. Better to get it stopped now than have it come up in an exam. Obviously remove all of the 2017 entries that are being reported by the purchaser.
Going bak to previous (already filed) LARs is a risk decision.
You could not resubmit and take the risk of it being detected. Depending on when your next exam is, and assuming it is detected, they examiners might make you resubmit. If you haven't had to resubmit before, I doubt you're looking at penalties either way (resubmitting now or waiting - if it's detected).
You could call your local field office and ask for their opinion, but they you'll have to do what they say. Again, it's all a risk decision.
Answer by Andy Zavoina:
I agree that you correct what you have now so 2017 is correct, and you ask your field office. They may say the count is low and insignificant. They may also say, complete the corrections and keep that on file, plus share it with them so they can use the correct data when they examine you for fair lending and CRA as well as HMDA.
I have been in a discussion where the examiners wanted the corrected data but it wasn't worth a resubmission and certainly not worth reproducing all the tables again.
I believe what you do not want is an examiner finding the problem and that being the first they hear of it when the bank has known about the issue.