@Phoneman65 In another thread, @mkilo67 reported that after he installed this Tablo firmware update, his problem with FireTV Cube went away:
Tablo (4th Gen Only) Firmware Release 2.2.47
I have also installed that firmware update and (knock on wood) have not yet experienced playback failure issues. I plan to run a more extended series of trials this week. Feel free to follow us for additional info as we continue to use the system. Cheers.