Thoroughbred
Only the official HughesNet modem can be used with HughesNet. No third party modems will work with it.
Depending on the speed requirement for the video, you may see benefit by turning off, or snoozing, the Video Data Saver.
If that doesn't help, I recommend starting a new topic in the Tech Support section to see about troubleshooting the issue.
Please keep in mind that streaming is a very data intensive activity, especially if it's in HD. Going by Netflix's information, streaming in HD uses about 3GB per hour, SD about 700MB per hour, and LD about 350MB per hour. Also, please keep in mind that, during your first 20 days of HughesNet service, your service is in what's known as a "relaxed bandwidth state", which means that HughesNet is continually refilling your data allotment during this time. I believe hourly. This is done as a courtesy, in order to allow new customers to bring their devices current, whether through updates or upgrades or whatever else, without it affecting what would be one's normal monthly data allotment, as doing those things can use a lot of data. After these 20 days the data refills will stop and your data will start being counted, and deducted from your monthly allotment, like it normally would. The relaxed bandwidth state is explained in the Welcome email sent by HughesNet.
Hope this helps. :)