I’ve had my original 2 tuner Tablo since early 2015 and ever since it was available I’ve had the “Do not record duplicates” checked. Earlier in my Tablo years I was recording a lot of classic TV that I eventually moved to my server. I only have a 1tb hard drive and at times it was nearing capacity. We now for the most part record shows that get deleted after viewing. I’m in a somewhat unique location where there are major networks 45 to 50 miles to my north and the same to my south. So I have duplicate channels for all the major networks as well as many of the sub channels. And I have all the duplicates I’m interested in, in the guide. I do have 2 excellent Televes long range antennas on my roof but in the summer months some channels are troublesome.
Recently we’ve been having troubles recording a certain show that’s on multiple times mid day~afternoon. The two (duplicate) Fox channels are ones that can give us trouble in the summer. One of them is VHF. I’ve tried programming it with a preferred channel (the better of the two) but the two channels seem to share their troubles so that did not work. I then thought hmmmm I should turn off the do not record duplicates thing and let it record all available episodes. I did and it’s been working great. Every day now we get good watchable episodes.