Buffering and skip back on one channel

This behavior is getting worse. It is now happening randomly on different channels practically every time I watch TV. Recordings seem to be fine, but it’s getting to the point I can’t watch live TV on the Tablo anymore. When I switch to watching the same channel directly on the TV tuner, everything is fine. No glitches or stutters or anything.

So what is going on I wonder? If there is an external drive issue, why are recordings fine but live TV is faltering? It is obviously related to the real time recording of live TV, as it gets “stuck” in a playback loop that is difficult to get out of.