First, there is no such thing as a "joint" HSA - the HSA belonged to either you or your husband (probably your husband from your description). So was this his HSA or your HSA?
You each must be an "eligible" individual to contribute to each other's HSA. That is, you must be covered in an HDHP and NOT have other coverage (such as regular employer insurance) to contribute to anyone's HSA.
I can't quite tell if you were still in an HDHP, or if you dropped out at the same time your husband (remember, the HDHP coverage can be shared by the Family, but the HSA can belong to only one of you (of course, each of you could have a separate HSA).
In any case, in the HSA interview, it asks about the primary taxpayer's coverage, month by month if necessary, and for the spouse also HDHP coverage. If it turns out that you made contributions in excess of your recalculated limit, then TurboTax will tell you that you have an excess contribution.
TurboTax will next ask you if you want to withdraw the entire amount of the excess before April 17 2018 (note, it will ask each of you if it determines that you each have an excess contribution). If you say "yes", then the amount of the employer contribution (and your payroll deductions) will be added back to Line 21 as Other Income, so that addresses that issue.
If this occurs, then need to contact your HSA administrator (BEFORE APRIL 17) to report a Mistaken Contribution (if you say "excess contribution" they will still know what you mean - just don't say "distribution"). Be nice when you ask, because they don't have to do this. Then you will receive a check from the HSA administrator, and you will deposit it in your checking account.
Since the excess is now reported as Other Income, you are done.
