Blinking is not normal. My people run around in world all the time for hours on end without a blink.

Since you are doing a SP --> MP port (which I wouldn't recommend), you may have some bit of extra code lying around somewhere that is causing the blink. Even with 3DGS controlling your ent fully this may lead to jumps and teleports as the client re-synchs with the server position but nothing that would be described as blinking.

Check over your code. It's unlikely to be engine related.