Nevermind, I have noticed I also can't buy the damage converters (ice chunks and such). The prompt to buy shows up, I press "Yes", but don't get the item.
But I believe I have fixed it also by rechecking everything is up to date 🙏
So in game settings I've specified not to pick up white (common) loot... but it doesn't apply to rings and amulets. Is it related to the increased loot variety in Addendum?