were you covered only by a HDHP for at least 6 months in 2023 (the monthly proration when you have only eligible coverage is $321 per month)? if you were not covered by a HDHP at all in 2023, the excess from 2022 and the employer's share become excess contributions. if you were covered by a HDHP did you check off the type (self-only or family) for each month so covered in 2023? if not Turbotax thinks you didn't have any qualifying HDHP coverage. Were you covered by Medicare or any other health insurance that were not HDHPs for all of 2023, if yes it doesn't matter that you had HDHP coverage. Being on a non-HDHP for all of 2023 makes the $1700 contributions excess. if for only part of the year you had non-HDHP coverage then a prorata portion of the full year amount is disallowed.
certain non--HDHP coverage is allowed that only covers the following:
accidents
disability
dental
vision
long-term care
telehealth and other remote care
liability insurance related to torts, workers' compensation, or ownership or use of property
specific diseases or illness
a fixed amount per day (or other period) for hospitalization
