This still seems confusing:

"The nondeductible contributions still must show up as excess deferrals."

"it was moved to a Roth just a day ago."

Have you confirmed this qualified under the megabackdoor rules, then? You have two different employers, and the employer limit is per employer, even though the employee limit is per employee. If it was megabackdoor, you have that combined limit.

But then you tell us:

"So, it was not taxed"

Not Taxed means moving it to Roth is an In Plan Conversion and would be taxable at that point.

Megabackdoor means Taxed funds put into a 401(k) as Basis, then moved to the Roth 401(k) with no tax consequence.

So, which is it:

This is on the W2 as pre-tax, and the pre-tax from two W2 exceeds the employee limit.

Or,

This is a post-tax amount, and was a megabackdoor contribution.