If the Live TV guide grid displays Unknown Airing when connecting from iOS, and Roku, then the problem is probably at the Tablo itself.
3 things to try, and check for the Live TV guide grid issue:
1. On your Tablo's settings page, is Subscription displaying as Active Subscription?
2. Briefly press the Tablo reset button to reboot it.
3. Change the Postal Code to one that is not yours, but is close to yours via the Edit Location button on your Tablo's settings screen.