In TurboTax Online and Desktop, some customers are experiencing this issue:
After entering a K-1 form and choosing AC ("Gross Receipts for section 448(c)"), you might next see a screen for "Other Situations," instead of "Enter Code AC Detail." Then, if you choose AD (“Other Information”) and select Continue, you see "Enter Code AC Detail."
Don’t worry, this issue is being worked on! If you’d like to receive progress status updates, please sign up here.