Do you have Media-on-a-Prim enabled? If yes, can you please disable it and check if the crashes still happen?
When a video stream starts, your computer has to fill buffers first. That can cause a short spike in Internet bandwidth usage. If it's high enough and your connection slow enough, that could cause other data packets to be lost.
I don't think this is likely to happen, but it might. Just wanna make sure.