In 2020 there is more 179 depreciation than there is business income so on form 4562 box 13 there is 19,501 (carryover of disallowed deduction to 2021. My schedule M-1 line 4a has 19,501 (expenses recorded on books this year and not included on Schedule K etc. line 4a depreciation) because of the 179 limitation  and line 9 Income has zero. Re Schedule M-2- on screen 28 I checked the box recompute Sch M-2  line 3 if partnership books are not on tax basis. When I do this Schedule M-2, line 3 ordinary income is 19,501 greater than the book net income on line 1 of the Schedule M-1. But I took a look at what I did and the balance sheet is now out of balance due to the tax basis capital accounts. Now I am really confused.  Do I need to check the box to "recompute Schedule M-2 line 3 if partnership not on tax basis" since difference tween books and tax have to do with a 2020 Section 179 c/o to 2021? I thought my tax returns were tax basis but got confused when I had a 2020 Section 179 c/o to 2021.   

Thank you for your help.