Prism of Belief Diamond Not working

I tested a +3 to level hexblast and it increased my hexblast level from 30 to 33 but the tooltip dps did not increase and the mana cost of hexblast remained the same.

I also tested a +2 to level hexblast and the skill level increased from 27 to 29 but the dps did not increase nor the cost of the skill. The Prism of Belief jewel seems to not work at all.

Hi hexblast friend i test this too.
This jewel is WORK.

Damage up if you unqupment weapon or amulet with + gems and equp again, or you can teleport to another location and last way in tree node "Dark Entries"(+1 chaos gem) up or refund and up. After recalculate, hexblast damage work correctly.

gl exile

thank you brother! It works