(Note: I've only tried this with swords, but I'm extrapolating my experiment to all items)
Let me explain: Level 1 items only trigger (all) triggers of their respective types, Level 2 items only trigger (Level 2+) items, etc.
I'll post the quest I made to confirm this bug if I need to.
(809) - Same-type weapons only trigger flags of their level
This must be related to when I fixed the Item Override-related bug.
Still in 819.
Confirmed. It happened to me playing a 1.92 quest in 816.
Confirmed again. It happened to me when I was playing a 2.10 quest in 819.
...Possibly fixed?