(Client is left, server is right)
Basically, I have a sound object that starts the game embedded in a part inside of ReplicatedStorage. When a house is loaded into my games, this part gets moved into Workspace by the client entering the home. For whatever reason, every property of the Sound object replicates except for the Playing property. This means I can't have the server toggle playback controls on this sound for every player that sees it.
As you can see in the gif above, I repeatedly toggle the Playing property and no change is exhibited in the client. However, toggling the looped property and changing the MaxDistance property does change what the client sees. this bug also applies to :Play() and the like.
Attached is a repro, you can test it using F7 mode, try dragging the part into Workspace on the client then try toggling the Playing property on the server, the client won't see the change.
PlayingNotReplicating.rbxl (11.2 KB)