YouTube issue with my ISP

Hi all,

My ISP provides a service called "YouTube Unlimited", in which they provide 30GB of data for a certain cost for HD streaming, and unlimited data for non-HD streaming. Since lately (I'm not sure if it's after I upgraded to windows -- around that time, anyways), this YouTube Unlimited package seems to be dysfunctional. No matter how much I stream in HD the data won't show depleted, and it looks like that data is spent using the normal background data (which is outside the YT Unlimited service). This is the YT-Unlimited package I've installed on my Laptop's modem/sim, but the same package installed on my Phone works fine -- so I cannot say it's a defect in the YT package (Both connections are mobile, my laptop uses a dongle to directly connect to the net, and my phone use a separate SIM). So I called the ISP and they are saying that in their systems they cannot detect any Youtube activity on my connection -- and that's why the YT data is not depleting. The customer service cannot seem to figure out why they are not registering my YT usage. Does anyone have a clue what's causing that kinda thing (me using Youtube and the ISP not registering that I am)? I'm not using VPNs or anything when I'm on YT. And I'm using both Firefox and Opera on YouTube (So it's not a browser problem either).
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Hope my question makes sense.

Thanks!