I had a similar problem after I entered two K-1s (call them "A" and "B") for two trusts. The gross foreign income from A flowed through to my 1116, but the gross foreign income from B did not. I then noticed that A had a box 14 B entry, and that B did not
I contacted our CPA, who said that because the beneficiary allocation of some assets from B was not in equal parts, her software would not allocate the foreign taxes to the beneficiaries, and it would have cost more to fix it than the tax credit was worth.
I double-checked B's 2021 1099-B, verifying that foreign taxes were paid, then experimented by adding a box 14 B entry on B's K-1 in turbotax. I found that if code B was present, and set to $0, then the gross foreign income would flow to the 1116.
I was worried that the IRS would gripe about the K-1 not including the code B entry, but when I went back to the K-1 in "Forms" after the value had flowed through to the 1116, the code B entry had disappeared (probably because it was $0), so it appears to be ok.
