Spatially loaded characters unresponsive

Sometimes, perhaps after unloading, the newly loaded AI is unresponsive, or only partially active - meaning they move but take awhile to response, i.e. on attack they take several minutes or finish current goal of pathing.

But when the spawn is active, the current cell is fully loaded and the player inside, newly AI behave as expected. This suggest that somehow they are not fully loaded or initialized.

Is there perhaps a BP node for onload force behaviourtree execution? Has anybody else come across such an issue?