HSA confusion with taxes and reporting

Hi!

My workplace contributes to my HSA every pay period when I have a HDHP. I finally swapped over to the HDHP starting January 1st, this year.

My December 23rd paycheck shows a contribution, but it didn't show up in my account until January 10th (my next paycheck). It also means my W2 for 2025 shows a HSA contribution, but I didn't have a HDHP.

I feel like this is incorrect? I want to file my taxes but I'm worried that I'll get in trouble for employer HSA contributions that A) were on a 2025 paycheck and B) didn't even happen.

My payroll at work says it's normal, but I don't really understand why it's ok.