I have found that when the Gen 4 gets glitchy (can’t find Tablo, can’t find shows, and just generally craps out), if I power cycle the Tablo, things kinda clear up. It happens so often, that I now will do a power cycle first thing in the morning, every day. This thing has so many bugs, no exterminator would touch it.
Totally feel your frustration i have had similar issues with the Gen 4 acting up power cycling definitely seems to help clear things up temporarily but it is frustrating to have to do it daily just to keep things running smoothly. Hopefully, future firmware updates will iron out some of these bugs. In the meantime, some folks have had luck putting their Tablo on a smart plug with a scheduled daily reboot might save you the hassle of doing it manually every morning. Hang in there!