I had this problem - Three hours online with support no help.
You are going to hate this answer.
1. find last years list of items that were carried over and the amounts, it should add up to the number in the block.
2. Go to Forms Mode - Click 1065 Depr Opt on left column
3. Click the plus to the left of the number in "Federal Secion 179 Information" items 4a and 4c
4. Enter each item and the carryover amount as applicable.
Sorry I agree this should have autofilled in but this is the only way I could fix and e-file
