Disappearing items

Ever since I joined this server there is this bug. You have items in the bag, you enter bg or arena and the item/items disappear.
Example: I play holy paladin on 2v2 and 3v3. The gear is different on both types so if I forgot to change gear before arena, in the arena items are missing, and I can't change gear...
Example 2: It is 99% the chance if I enter with one-hand + shield (on warrior) in arena my two-hand weapon will be missing (did that few times and I no longer enter one-hand + shield). It is also if I enter two-hand sometimes my shield or my weapon are missing...
Example 3: Sometimes it is my food for mana or my ammo.

Here is video to see that my wrist (cloth), wrathful shield, wrathful weapon are disappearing.. https://www.youtube.com/watch?v=WKrdFAB4gDw

In order for this bug not to appear, you need to clean the first bag from the trash. and put important things into it (weapons, shield)