Pixelating recordings - live is fine?

Have a legacy dual-tuner tablo. All was fine until recently. Recordings are pixelated, choppy and unwatchable. I originally thought reception, but if I watch the same channel live, its fine. I was watching a recording of a show that started 15 minutes earlier. The recording was awful, but the live was fine. I have fast cable internet. No changes to any settings on the Tablo nor the router/modem. Any suggestions?

How old is the hard drive?

Its the one that came with the Tablo. I have had it 5 yrs.

You may want to contact support on this one if the HD is internal to the device.