Hi. I don't know if this will help anyone else but I was having the same problem withe 16B. Just FYI and for search, it was IEP (Icann Enterprises). I had non-zero values for B, C, F, I, and J and I was determined not to fill out K-1's for each box. That was crazy. I had originally imported the K-1 via TXF file and in the end the fix for me was to delete all of the lines that had 0 values. The import crated a lot of 0 values and apparently TT isn't smart enough to understand that "0" is the same as "not important" and deleting them fixed the problem.
This problem was posted in 2019 and it's now 2021. :(