Interactibles are SceneComponents, as such they requires a few things to be true in order to correctly replicate.
First of all, their containing actor needs both ReplicateMovement and Replicates to be true. Otherwise they will not be correctly updated on joining a session (unless they are the actors root component). This is just a side effect of how the engine updates child components.
Secondly, on the Interactible itself (Lever, Button, Slider, ect) it needs to have ComponentReplicates checked, this allows it to send its initial transform and settings in so that it syncs up with the client.
Something to note is that ReplicateMovement is unchecked by default, this is to avoid the engine sending relative locations and rotations during grip by default and wasting bandwidth. You can turn it back on at any time. In later plugin versions this will be defaulted to true and will be automatically turned off when being gripped by a non ServerSide grip type.
Lastly, the containing actors mobility also needs to be set to Movable, this is another side effect of how the engine updates child components that aren’t the root component.