your employer contributions are reflected on your W-2. code 12W which carries to line 9 of the HSA form 8889. you do not enter them as personal contributions.
your maximum family contribution - employer and personal - for 2023 since you started on Medicare in October, assuming you're over 55, is 8750 times 9 divided by 12 or 6562.50
did you use the last-month rule for 2022 to make a full year's HSA contribution? If so you had to be covered only by a HDHP for all of 2023. if not some of that excess comes back as taxable income.
were you on only a High Deductible Health Plan for the first 9 months of 2023? it's required. certain specialty types of insurance are allowed like dental and vision. A non-HDHP medical insurance plan that covers you is not allowed such as a spouse's non-HDHP
Were you covered by a Flexible Savings Account that covered medical expenses for any part of 2023? that disqualifies any HSA contribution.
we can't see the form or your answers so review the tax form and then check your answers.
