I've had the same problem with my four as well as my two tunerTablos, in both cases having uncommitted tuners available for transcoding. The consistent pattern is that playback remotely works fine for a while, confirming that adequate Tablo hardware resources and cell phone bit rates are available. Then, abruptly, playback suddenly quits. No timeline scrubbing or other iPhone player app contact is going on to provoke this. Playback just suddenly quits. Getting it started again is next to impossible, and I will not allow myself to become distracted while driving in the car to reboot or do any other Tablo app manipulations.
Before the update, I did not have this problem. Now I have it constantly.
Also, when using the iPhone as a playback device at home over Wi-Fi, I now also occasionally have abrupt quits . I also have very sluggish timeline scrubbing. These have worsened with the update.
My iPhone is a 6+, latest iOS 10. My performance on an iPad Mini fourth latest generation with iOS 11 is a bit better.