Hi,
Based on your description and my search, I don’t find this cast problem has something to do with Windows 10 system.
Please let me see, you upgrade to Sky Q from Sky +, then, you meet with a problem that you couldn’t cast to device, if you didn’t do some operations on Windows system, this condition is linked to Sky Q itself obviously, therefore,
you contact them for support is wise.
Meanwhile, because Sky Q is not a product from Microsoft, we don’t have condition to test for you, maybe Sky community is a proper place to ask for assistance.
http://helpforum.sky.com/
Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
Regards
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