Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

My character Thrar Zyrustane baught a longbow from the action house, the item name is Zalantar Longbow of Arvoreen's Wit.
It has a +3 enhancement bonus, +4 mighty and +1 constitution.
When i equip it it gives no bonus hp, when i unequip it, i lose my character level in hp, the max hp remains the same, i just get hp damage.
My character has 12 base constitution, and already has a +2 con item equipped, so the extra +1 from the bow shouldn't matter.
When i unequip the +2 con item the bow acts normally, and doesn't eat my hp when swapping it for other weapons.

I would appreciate it very much if a DM helped me out with this item.

you can't wear multiple CON items if you already have say a con +2 item already on it will actually hurt you equipping and un equipping it.

You can request a DM to remove the +1 CON from your bow to avoid that kind of issues.

The problem is resolved, Thank you DM_Hope.