Changed Modem and now My Cloud LED Never Turns Blue

My ATT service swapped out my modem with their newest model and ever since the My Cloud LED binks yellow. If I connect with an eithernet cable to my laptop it turns on blue and shows up in Explorer. How can I get it to recognize the modem via the eithernet cable so it will display on my network? Is there something I can do through my wife’s laptop when it is hardwired to it that will fix it? Is there something in the My Cloud setup or is there something about the modem that makes it not compatible with the My Cloud.

I put the TP-Link 5 port Gigabit Switch in between my ATT Modem and the WD My Cloud drive and now I am able to get the LED to be blue and I have access to My Cloud via WD My Cloud software. However. I cannot access the My Cloud via windows explorer nor the WD My Cloud Dashboard. The address for the WD My Cloud drive must be changed with the Switch in line. Can anyone tell me what the new address might be or how to find it and set it up in the Cloud Dashboard?

Go to whoever your DHCP router is, usually this is the router. There search for the DHCP lease table/client lease/client table. In a few words, it will show you list of devices using an IP from your DHCP range and who those are and its IPs.