Hoping for fix on this also. There are some workarounds (), but it would be great to get native multiplayer and platform behavior work nicely together.
Try adding local variables to track player input instead of applying the player input directly to the player objects.
For example:
If pressing left > platform move left
instead try:
if pressing left > set Player localvar to -1
if pressing right > set Player localvar to 1
if not pressing left & not pressing right > set Player localvar to 0
if Player localvar = -1 > platform move left
if Player localvar = 1 > platform move right
It's more steps, but it's also a LOT less data to send for online multiplayer, since you're just checking on/off state when they occur instead of continuously.