Exactly when did the excess contribution ($75?) actually get deposited into the HSA. If it was in 2022, it's impossible for the HSA custodian to have re-designated the excess as being part of your 2023 contribution but would instead have to perform a reportable return of excess contribution and apply the proceeds of that distribution as part of a new contribution for 2023. The result of that would be the same as if they had given the $100 cash to you and then you gave it back to them as part of your personal 2023 contribution.
Exactly when did they do this "roll forward?"
Given that they seem to have treated $100 as a 2023 contribution, this would imply that they did a reportable return of $75 of your 2023 contribution accompanied by $25 (33% investment gain!) of attributable earnings with that $25 being reportable on your 2023 tax return as income, reported to you on a code-2 Form 1099-SA with $100 in box 1 and $25 in box 2.
