You can find more be searching for “split screen”. FYI, here’s another thread.
This issue can be very annoying. You are at the mercy of the station, just hope they’re open to changing their broadcast parameters.
I had a local PBS station do this and had to alter my scheduled recordings for a while to keep the Tablo from trying to tune the “bad” channel. Also, in my case once the Tablo rebooted because of this issue I had to do an unplug power reboot as some recordings on “good” channels would be affected (like there was a memory corruption that could only be cleared by pulling power).