What HSA contribution are you trying to remove? The "employer" contribution (which includes your contributions by payroll deduction) is in box 12 with a code of W on your W-2.
When you get to the screen in the HSA interview that says, "Let's enter [name]'s HSA contributions", you'll see that the first line says "2023 employer and payroll contributions". The amount here comes straight from the code W amount in box 12 on your W-2. As you may have noticed, you can't change this here, you would have to go back to the W-2.
The second line says "Any contributions your personally made". You should have no problem changing this value.
Or are you talking about something else?