[Dumyat]

Are you able to test this as well, ie change the status of an un-watched movie to watched within one of your movie sets and see if the total watched count then increases? If you do see the same thing happening, what would be the best way to clear the skin helper data just for the movie sets?
Again, your input is very much appreciated.

I found the problem, some time ago caching was added to script.module.metadatautils by SHS.
I don't think the original author intended this. Because it prevents the data from being updated quickly.

Excellent....All working now!
Can confirm I'm now seeing correct watched amounts now and that watched count changed immediately when I made an update just now.
You are a pure genius for identifying the issue so quickly...thank-you!
Actually glad it wasn't something I had done incorrectly or something wrong with my set-up. 
That must be another beer or two I owe you now then! 
Do you have write/update credentials for the SHS on the GitHub to update this file?
Thanks again. Much appreciated!
Cheers