By the way, I have a fix for your issue in the pipeline. I should be able to enable it in about 1 week.
The fix prevents any catastrophic behaviors but there is still an imperfection with what happens when NPCs change ownership while on a moving platform. Essentially due to latencies involved in changing ownership NPCs may drift behind the platform for a few frames until new data arrives from the new owner. Minimize NPC ownership transfer to optimize for smooth visuals!
The bug that I fixed was causing these characters to teleport to the origin positions of the platform, which was causing the boat to be jittered and shot around, and this should no longer happen.