Hi, i was having the same issues with iptv cutting out not just recordings, you want to Pipe with ffmpeg, add this in the URL in your iptv mux.
pipe:///usr/bin/ffmpeg -loglevel fatal -reconnect 1 -reconnect_on_network_error 1 -reconnect_on_http_error 1 -reconnect_streamed 1 -reconnect_delay_max 4294 -fflags -nobuffer -flags low_delay -err_detect ignore_err -i <add your stream address here>-c copy -f mpegts -tune zerolatency pipe:1
Your channel switching will slow down but your streams will should be recordable.