I will report an interesting artifact using your query. I was testing it out and sometimes:
{
"_cursor": "",
"clips": []
}
This will happen a few times it seems (by few I mean, 1-5 times) in a row and then I start to get data back again. Otherwise, this morning, all I am getting back when I do get data is a few clips for RocketStreetLive. I have not tried to scan each channel though to see what they are returning individually.