Not a bug. As of now we don't really support AI-driven (pathfollowing/avoidance) movement for player characters in networked environments.
When running a Dedicated Server in PIE while using RVO, the Player character doesn't move at all. When RVO is disabled the Player is able to move but it is laggy.
Result: Player doesn't move at all, as if it had no input what so ever.
Expected: Player moves to location.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-55221 in the post.