Aha I’m pretty sure I have found my problem!
Though I haven’t got the fix yet I’m super happy to at least have identified the issue. When I force the last bit, the one we have been looking at, to only execute only on the client it just doesn’t play at all. It’s something to do with it not being the owner of the client and attempting to do a RPC I reckon.
When it was working in the example above when setting the var directly it was actually playing and replicating the animation off the server.
When I thought I made it work I actually didn’t and it kept me thinking in the wrong way.
I’ll change how I do this tomorrow but I’m pretty sure there won’t be any trouble.