You must reduce the amount you, or any other person, can contribute to your HSA by the amount of any contributions made by your employer that are excludable from your income. This includes amounts contributed to your account by your employer through a cafeteria plan."

It seems there is going to need to be a corrective distribution or perhaps they can apply it to this year.

I also like "consumer grade" instructions, such as:

https://www.kitces.com/blog/health-savings-account-both-spouses-coordination-limits-high-deductible-...

"For spouses covered by separate self-only HDHP plans, each can contribute up to the maximum, self-only limit to their respective HSAs, but they can’t make up for any contribution shortfalls of the other spouse.

Sometimes, one spouse might have self-only HDHP coverage and the other an “employee-and-children” family HDHP (which does not offer coverage for the employee’s spouse). This can be cost-effective for couples with children, as family HDHPs sometime provide for “employee and children” coverage that is less expensive than family plans that include both spouses. In this situation, the spouse with self-only coverage is limited to the self-only HSA contribution amount, and the spouse with family coverage can contribute up to the family limit. But while the total between spouses cannot exceed the family limit, the spouse with the family plan can make up for any contribution shortfall of the spouse with self-only coverage.

In rare cases, both spouses may each opt for separate HSA-eligible family HDHPs through their employers (perhaps because of different in-network doctors offered by each plan). Again, the total contribution between spouses may not exceed the annual family limit, but in this situation, both spouses have the ability to compensate for any contribution shortfalls of the other, or to simply choose which spouse’s HSA it makes sense to fund first."