You make some alarming statements!
I disconnected it and deleted it from all devices, and had to reset my actual network.
Yikes. Not sure exactly what that indicates you have done, but yikes.
If the device worked plugged into your TV, it should work plugged into AVR via the HDMI switch. So you shouldn't expect to see a configuration screen. It has already been configured as a DHCP client on your system and it doesn't care where its HDMI output goes. That is assuming that your Chromecast device can see your WIFI from where it has been relocated.
Have you tried plugging the device back into your TV where it last worked ok? If that no longer works, then you'll need to rerun the configuration software.
If the device works directly connected to the TV, then this statement
When I switched to plugging it in to my avr with the hdmi switcher, nothing on the screen
is the next point to investigate.
First the really obvious question: Have you made sure that the HDMI switch is switched to the port that the Chromecast device is plugged into? Kinda sounds like it may not. Try switching to every port while the device is plugged in and see if the Chromecast display isn't found. The HDMI switch probably has buttons on it to discretely select input ports or a button to rotate through the ports. You might even have a remote with the HDMI switch to do this.
If that fails, try pluggijng the device into another port or swapping the ports that your DVD player and Chromecast device use. Can you still find the DVD player but not the Chromecast device? If you have a bad port, you should be able to exchange the HDMI switch for a new one.