• Logging into 192.168.1.1 doesn't always work. If I turn off the RUTX next time it's a mess and I get messages like "You're not connected to the internet" etc. Usually takes a couple of resets before it finally works again.
Most of the time this happens because your PC has more than one network interfaces which are fighting over priority on each other. So I would suggest setting static IP address on your network adapter. Other thing could be that your router is still booting up and you're trying to access WebUI that is still loading.
• Cannot get both SIMs connected at the same time.
As the router has only one modem - it can only have one SIM card active at the time. It is not technically possible to make them both active on RUTX09. This feature is only supported with RUTX12 as it has two modems.
• The status menu is confusing, it's hard to find the status of all three connections Wired WAN, SIM1 and SIM two, and it's very hard to tell which one is actually active? And sometime it seems like it's using Mobile instead of Wired then how to I make it switch to wired?
To set one of the interfaces as your preffered main interface you will need to go to WAN settings and move your preffered interface on the top. You will also be able to see which interface is active on this page by looking at the status and IP that is given to it.
If you're looking to set a Failover for your interfaces - you will need to enable it with the ON/OFF switch in the page for your preffered interfaces and also just move them accordingly to your priority.
I've read your use-case and Failover functionality is perfect for you. Just set those two interfaces to Wired WAN as main and active mobile interface as a secondary option and you will see that it should work. Also, once your Wired WAN is back up and running again - router will switch back to it and use it as a MAIN connection.
For SIM1 as main and SIM2 as backup scenario, you can use a SIM switch which will let you switch to SIM2 on events like weak signal or no network indication and etc.