Thanks Mike9241 for your detailed response, and for pointing me in the right direction: Form 8889.
When I went to the Forms View, I found that TurboTax had defaulted to "Family" coverage in Part III only for the month of December 2022. Therefore according to TurboTax I was probably failing the 12 month test since I had switched to Medicare (i.e. a non-HDHP plan) in Oct 2023, which then implied I had to pay a penalty for my 2022 HSA withholdings.
So I manually checked the "Family" option for the remaining 11 months in 2022, which seemed to fix my problem. I should also mention that I had to manually go through and enter similar information in 8889 for my wife as well and that fixed some more problems.
Needless to say, I'm not impressed with Turbotax and their customer support: I talked to 3 people in 3 different calls, and was sent on wild goose chases in every case. There does not seem to be a way to escalate when the answers from the first line of Customer Support are demonstrably wrong.
A segway to another grouse: I feel like TurboTax could do much better on the topic of Roth IRA contributions. I could not figure out how much I could contribute for 2023 without any tax implications. The best I could do was to put in different amounts for my wife and myself, and see if my refund changed. To me, that's absurd: TurboTax should be able to give me this information because it has everything needed to calculate the right numbers.
