This is not an IRA contribution.  A 401(k) isn't even an IRA.  Remove from Deductions & Credits anything you entered there regarding this rollover.  This rollover is entered into TurboTax only by entering the Form 1099-R and answering the follow-up questions.

If this message is not resulting from an entry under Deductions & Credits but is instead the result of entering Forms W-2, be aware that amounts with code D in box 12 of your W-2s is not permitted to total more than $19,500 if under age 50 in 2020 or $26,000 if age 50 or over in 2020.

I don't understand what you mean - I never said it was an IRA.  It's a 401K

your action was a Rollover - not a contribution.

if you enter a contribution, that's wrong.

There are two reasons that TurboTax might flag an excess contribution.  One is mistakenly entering the 401(k) contribution as an IRA contribution.  I addressed that in the first paragraph of my first reply and is the most common mistake that people make.

The other reason is that you contributed more to 401(k)s than allowed between the two employers combined.  I addressed that in the second paragraph of my first reply.

If the first reason doesn't apply, it seems that the second one would be the one describing the situation that you are encountering.