Tried to set up the recording on the Gen4 and it wouldn’t work, so I set the program before it to record and set it to end 3 hours late.
Then I went into the OG Legacy and saw that the Presidential Address is scheduled from 2000 hrs to 2022 hrs, right in the middle of the show. That’s probably the reason it wouldn’t work. The Gen4 schedule didn’t show the Presidential Address in the Guide.
Anyway, got it set up on both devices using the “End 3 hours late” feature.
Tablo Gen4:
Tablo OG Legacy:

