PoE2 target hit bug

I'm a Mana Stacker who uses Bone Storm. Besides the usual damage support gems, I use Zenith 2 to build up mana regen.
At some point, I noticed that hitting bosses or other big targets drains all my mana (I have 5-10k mana regen).
When I shoot into the air or at small enemies, everything is fine, my mana is at 90-100%, but hitting big targets drains all my mana.
Also, my damage on poe.ninja/poe2 dropped from 1.2kk to 140k, even though nothing in the game has changed.

https://poe.ninja/poe2/profile/Hisiel-1922/character/ГалинаКрепкийПалец