Hi mrm0rgan,
Welcome to Microsoft Community.
May I ask if you watch the video through the app or the browser? If this happens with Microsoft Edge, I suggest you try turning off hardware acceleration. You can click on the top right corner of the Edge... This button opens the menu and goes to Settings. See the image below to find the "hardware acceleration" switch.
Also, I want to make sure that when you open Task Manager during a screen freeze, do you see a lot of CPU/ memory/disk read/write usage in the process?
Your patience and cooperation are highly appreciated. We look forward to hearing from you.
Best Regards,
Manson - MSFT | Microsoft Community Support Specialist