Sporadic movement while actor attached to character

In my multiplayer game, when the server character has an actor (such as a helmet) attached to its skeletal mesh, the clients see the server character running with spotty movements.
The server does not see any sporadic movement on its own character from its own view.

To fix this problem, I went to the helmet’s actor blueprint, went to its mesh, and in the collision setting called ‘collision presets’, I set it to ‘No Collision’.