Tvheadend

Hi,
I am running HTS Tvheadend 4.3-1979 ~ LibreELEC Tvh-addon v10.0.0.102.
I have an IPTV List with a couple of channels coming from different sources and showing the same content. They are not very stable, so sometimes one works and the other doesn't (that's why I have 2).
I would love to have a way to use channel 2 if channel 1 is offline while recording. I see that when this happens, TVH changes to a fallback IPTV #2 list (which doesn't exist, since I just have one list), so in theory something similar has been implemented but I am not sure on how I should use it properly.

So the idea is simple, you start recording from Channel 1 and if it goes offline or has a bad reception, you switch to Channel 2 and continue; if offline, you go back to Channel 1 and so on.

Thanks!