@GrandMstrJ 

The Deco can only create one subnet so there is not a way each device can be on a seperate subnet unless the devices are on seperate networks.  The only exception to this is on older version of the Deco Software the Guest network was a seperate subnet, this was done for security so Guest devices could not comminicate with the Local network.  With the most recent Firmware however this has been changed and we just add options to isolate the guest network from the local. 

@GrandMstrJ 

You are having a basic networking issue, not really a Deco thing.

You can run your Deco in AP mode to get on the same subnet as the wired devices. You will loose the automation features of the Deco though.

Or you could put your modem's router into 'Bridge Mode' but that (if a possible feature on your modem...) is rather complicated. Best to get some help if you try that route.