I didn't overfund my HSA but I'm flagged for potential excess contributions. Called up HSA and they don't see any excess contributions or withdrawls. Why update 8889-T?

I'm asked to check the 8889-T box 12 for amount that was withdrawn due to over funding my HSA. I didn't and confirmed with HSA. Do I put 0 for amount withdrawn or what's in box 12 of W2?