Blackmagic H.264 stops capture

I have a middle school TV lab and we use a Blackmagic h.264 to capture our daily announcements. Everything has run very smoothly for months. I got new computers and installed and got rolling only now the capture stops after about a minute and a half to two minutes. Our broadcasts are typically around 5 minutes but we are having to post in two files to get the whole thing. The new computers are the ones they use in our high school video game design labs and they have i&-7700 Turbo processor, and a HD Graphics 630 card. I've been researching the forum for possible answers and most of the technical language is above my knowledge level. Help. I did go in and check a box for dropped frames.

Disable all OS power saving. In Windows, you can also set the USB device in device manager so that the OS can't turn it off.
That should fix the problem.
Also, use the original USB3 cable that came with the device, or a very good quality one. Some of the cheaper ones that come with external disk drives I have found to be unreliable.