Quest action "make X permanent" refuses to trigger in S0000503

[JayH2971]

There's a problem in Former Student Part III with the quest action "Make X permanent," which is supposed to remove the quest condition from an item (remove green background, make droppable). It's not functioning here, and I don't know why. Sometimes it works, and sometimes not. These screenshots show me having the quest items in my inventory while no quests are active, which is supposed to be impossible. Since the quest is properly scripted and all events light up correctly, I can't fix it more than that.

Reproduction steps:

console command "startquest S0000503"
Complete quest until ending where you betray Baltham
Kill Baltham
Items should become permanent at this point, but they do not. They zombie in the player's inventory from that point.

Originally posted by @JayH2971 in #2719 (comment)