On 095 core NPCs can walk through movable chests, crates etc.
On 096 core they cant. So any player can bring some chests in dungeon, for example, put it on the ground around himself and no one monster cannot hit him.
Does anyone have any idea to solve this problem?

Simplest method would be what OSI does.

In the AI scripts check to see whats blocking movement. If it's an item that is not locked down, destroy it.

There might be some other things to check before destroying it, but that it the basic idea.

make the monster loot the item in the ground

OSI methods....... they ignore all container types on movement. I would have to double check if it is static also, but normal items (locked down or not), they ignore and walk anyway. Nothing is destroyed for this.

Maybe we could look into this further, and see what we could do about it. One thing it does (on osi) is stop the trapping of npcs. So I would have to investigate their current behavior (far as static items), and see how it goes. Would also need to double check for players too. Don't pay attention must for my own walking