"I took the 2023 RMD from the combined account."
Whose RMD? If it was your husband's RMD, that was required to be distributed to you before rolling over the remainder and the RMD was ineligible for rollover, and your husband's 401(k) plan was responsible for enforcing that. Rolling over the RMD creates an excess contribution that is more complicated to correct than just taking a regular distribution.
The code 4G Form 1099-R is reportable and should show a $0 taxable amount. However, the form is incorrect if the amount in box 1 includes an RMD that was ineligible for rollover.
What is the code in box 7 of the Form 1099-R that reports the distribution that you requested from the combined account? Is the IRA/SEP/SIMPLE box marked?
