So failover is really only 1 way as the primary single modem detects an issue and I assume flips to the second SIM and hopefully that works. It if does then it is stuck there as SIM 1 can never come back online anyways with only 1 modem in play. Good to know, a shame the 1 direction failover limitation wasn't so clear.
To be honest the RTUX09 is acting as a failover unit for my VDSL connection. A 2 SIM failover is a bit overkill anyways. :0)
Appreciate the response, loving the device. Nice and solid, worlds apart from the consumer junk that is out there. Netgear and TP-Link I am talking about you... ;0)