AA Gift of Mana (new rank) is not reducing spell cost of 116+ spells

I have noticed on my 116 bst casting 116 spell Akhevan Blood is not reduced to a cost of 1. I did buy the last rank of Gift of Mana.

Works fine for a cleric I just tested. Guileless Remedy (116) procced Gift of Mana (120) and made the next G Remedy cast cost 1 mana. Even tried casting symbol after a proc and still just 1 mana (no cost basically).

Remember ... if you are casting a 111-115 spell, Gift of Mana can fire but it will be the 111-115 version and thus not work for 116+ spells. And of course, you also have to buy the 13th rank of the aa.

I think I figured it out. When you cast a 116+ spell, the Gift of Mana 120 bonus is given, applying to only 116+ spells. When you cast a 111-115 spell, Gift of Mana 115 bonus is given, applying to only 111-115 spells. So this is probably working as designed, it is just a poor design. Even at 120, you will be casting the occasional sub-116 spells. To take enchanter as an example, that would be dicho and slow. So the gift of mana you get from those occasional casts will be wasted. It would be much better if Gift of Mana 120 could be triggered by a much wider range of spell casts, and apply to any spell cast from 120 and below.

So, it does work on lv 120 and lower.
https://www.raidloot.com/spells?name=Gift of Mana (120)&effect=&class=&level=&view=