Why my ai start Moving only after player dies

Hi,
i have a problem with my ai in Multiplayer on dedicated server.

in editor the ai works fine, but in Multiplayer the ai start to work only the player dies once.

spawned npc after player dies works fine
Npc who has spawned before player died works also fine after he dies

the ai use a nav mesh with abstract nav data and is spawned by the spawn ai node and runs a behavior tree
the behavior tree is running before the player dies

its just a movement problem i think