It is quite possible your OTA signal is low and you may need to see if you can get it raised to an acceptable signal strength. During heavy downpours, I wind up recording off the OTA as the sat signal drops out a lot more than the OTA does.
The real big reason why I won't use a OTA tuner is because it ends up making my 612 receiver unstable. I sometimes get random reboots when adding OTA stations. Also when I switch from OTA to Satellite back and forth it would sometimes go into a endless Acquiring Signal checking spotbeams and just stay there keep checking until I did a force reboot. It did it one time I was recording something and the only way I was able to get out of the Acquiring Signal screen was to force a reboot and end my recording. After that I had enough and I deleted all the OTA stations, disconnected the antenna from my receiver and reconnected to my TV.
A reliable Over the Air Digital signal is a royal pain in the butt to pick up. That is what I have learned the past few months. This is why I only have my OTA antenna hooked up to my TV. So for me I use 2 Satellite tuners. I would not trust recording anything OTA. I would rather chance recording off the Satellites during a storm.
I take it you don't believe that where you live, what kind of antenna you have, where you mount it, how long the lead is, how well you aim it, how far away and in what direction the stations are and their radiated power is or the nature of the landscape in the area have anything to do with it.