Disappearing bonuses after changing character or teleporting

[Werwolf94 12]

Hi Guys!

I think you didn't see similar before because my problem is too rare (I googled for solution, and I searched a lot to solve it at similar forums).
So the problem is when you add bonuses to your weapon (or something else), and you go to another map or you simply log out, the bonus will disappear.
But if you put into your safebox, or you drop the thing to the ground, the bonus is still remain in your item, so I think the problem is somehow "attached" to
the player's inventory.
I maded a video from it, you can see it what am I talking about:

I have two systems in both server and client side, the slot marking system, and the system which is mark the new items which you buy or pick up.

(Sorry for my bad English I'm Hungarian.)