Just went through the same issue w/ Tablo support on my 2-tuner unit. I am in a forest where the signal can be at 100% signal strength, but it will drop to zero when trees move in the wind. The unexpected surprise is that a "bad" signal sometimes causes the Tablo to reboot. This causes fragmented recordings on "good" channels being recorded simultaneously with a bad channel. Reboots also kill anything you are watching. After the reboot the Tablo will retry scheduled recordings sometimes causing a reboot every couple of minutes. This is a case where "good" might not mean a "strong" signal.
The same TabloDVR worked AOK in the Denver metro area with less frequent signal issues. In Boulder CO I still have to re-point my antenna when the summer foliage fills in. I also select the UHF feeds for 2 of our VHF primary channels. I also select local low power translators for the 2 PBS channels. I'm down to a few days a year where recordings are degraded or failed.
At my forested rural location, I installed a 2nd 2 tuner Tablo to record my reliable PBS feed while recordings are hit and miss on my weaker stations on my primary Tablo. Using 2 Tablos is not ideal, but it added 2 tuners and allowed me to point antennas in two directions, one with a clear shot without trees. More importantly I have one Tablo that behaves on my "good" channels.
This is probably a firmware issue for the 3rd party tuner chip that Tablo uses. A "bad" signal should never cause a reboot which causes the fragmented recordings.... A "bad" signal should cause a poor quality recording, or a "failed" recording like I sometimes get. Tablo could improve their software to stop trying to record after one or two reboots, vs. generating multiple fragments. Tablo could also post-process the fragments into on recording w/ large gaps in the content.
Similar issues are reported for Tivo et al... and the old SimpleTV had a very poor tuner.