unless I am reading this thread incorrectly:
1. You contributed to a 401(k) - part into a pretax 401(k) and part in a Roth 401(k). If so, the maximum you mentioned is correct and your payroll provider properly reported it with code D for only the pre-tax and code AA for the Roth 401(k).
2. It sounds like you may have answered a question elsewhere in turbotax about either a Roth or IRA contribution. You should answer no to all of those, since your contributions were all done through the employer.
3. If I am correct in 2, then once you delete the yes responses then turbotax should no longer show you overcontributed.
4. You shouldn't need to do anything else other than correct your answers and do not need to withdraw anything from your accounts. The recordkeeper (like Schwab, Fidelity, Vanguard, etc.) also could confirm this for you.
Good luck
