"Seems like I will have to investigate more as to why TurboTax 2022 put the 1099-R RMD on form 8606-T."
Unfortunately, TurboTax does not rely in the code 4 to indicate that the distribution is from an inherited IRA and instead requires you to confirm that the account is an inherited account by answering Yes when asked the poorly worded question, "Did you inherit the IRA from [financial institution]." It's a mystery why TurboTax doesn't just believe the code 4. TurboTax asking this question for a distribution from a traditional IRA just creates the potential for user error and provides no benefit.
