It’s because of this. That means to only record the airing that matches the time of the specific guide listing you clicked on to generate that recording schedule.
However, it is not possible to record the same episode twice, so even changing the above won’t help. This is not going to be possible.
Oh sorry. When using that setting, you need to specify which airing time to use. It’s not based on which listing you use to crate the recording.
If you have it set to any, which is the default, it will record the first one. It will only then records the second one if the first one fails or if the second one has a higher quality and you’ve enable that setting.
As mentioned, there isn’t a way to force Plex to record and keep both.
with two tuners if one recording fails it should then record the next instance. Also, when adding tuners, always add the primary tuner last as this is the one it will go to first if it has multiple tuners with the same channels.