Thank you for helping me look into this.
I didn't get a message of excess contribution but couldn't consider other reasons. I didn't have HDHP coverage in the past so this should be the reason either.
I did test adding 0 as a year-end value, which would change the total distribution value in the HSA summary page at the end of the interview and result in a lower tax liability. So somehow my year-end value was considered as a distribution (on top of my actual distribution) by turbotax.
