I have more than one 4562 filled out with "Main home for form 8829" checked. Why is only the first asset flowing to Part III of the 8829?
Only one asset entered on a 4562 screen with Main home for Form 8829 selected will flow to Part III Depreciation of Your Home on Form 8829, Office in Home.
If the depreciation from more than one 4562 should flow to the 8829 as part of the main home (such as improvements, including replacing electrical wiring or plumbing, adding a new roof or addition, paneling, or remodeling) enter the assets on the 4562 screen and point them to the 8829 using the FOR field. Do not mark them as Main home for Form 8829.
When the return is viewed, a reference to an attachment should appear on line 42 (line 41 in Drake17 and prior) of Form 8829, "SEE ATT 8829". The attachment will provide item detail for the depreciation amount listed on line 41 of the 8829 (other than the main home itself).
See the Instructions for Form 8829 for more information: Also see Pub. 587, Business Use of Your Home.