If the AI Pawn is set to replicate and replicate movement, he should normal replicate the position etc. Since he is spawned from serverside, you will want to only replicate the states he is in. Make replicated bools, for Attacking Animation etc that only the server changes. Since they are replicated, the client version will also get the update and the AnimationBP will show the correct animation. The Client doesn’t need to know about damage or something, the server will calculate that for him. so everything that happens in the behavior tree should be done on the server and only the position etc (though replicate movement bool of the pawn) should be replicated.
At least that’s how i imagine it. It’s been a time since i tested that.