I have seen the same type of thing, I run a stereo and a mono feed from the same computer. On occasion one feed will drop while the other stays up. The best I can judge is somewhere a few packets got dumped in the bit bucket and the rest lose their way to the server. By stopping the feed and re-starting it, a new route is established and packets once again start making their way to the proper place.
IPV-6 is supposed to simplify much of the packet routing and prevent much of the packet loss due to routing changes. Now we just have to convince the ISPs to upgrade the last mile to the new hardware. I think the last time my ISP upgraded was probably about 20 years ago whey they hung bi-directional amps on the cable system and added DOCSYS.