This is a reply I just received from a Turbotax agent. If anybody has tried this please let me know if it fixed the form 3468 issue.
Have you tried deleting the K-1 and re-entering the information again? A recent update should have resolved this issue, but it may not apply to an existing K-1.
After you delete the K-1 and before you re-enter, check to see if Form 3468 remains in your return. If so, delete that form before you re-enter the K-1.
To re-enter Schedule K-1:
Return to the K-1 Summary page. Enter the K-1 and check the box for Box 17/20. Enter only one line for Code AJ and do not enter an amount. Continue to the page that asks for Other Information Detail. Enter a description and amount separately for both lines from Code AJ. Run Review/SmartCheck. If you receive a request for the registration number, enter TMXXX99XXXXX. Delete Form 3468 (either in Forms Mode using TurboTax for Desktop or using Tools >> Delete a form in TurboTax Online). Run Review/SmartCheck to confirm the error has been resolved.
These steps are easier if you are using TurboTax for Desktop, as you can make edits directly in the forms and easily see what forms have errors (red exclamation marks). But it can be done in TurboTax Online.
