Chromecast not appearing on network when connected to bridge

A

AC Question

Hey all!
I've been having a lot of issues lately trying to solve my chromecast woes. Hoping someone here may be smarter that I.
I have multiple chromecasts in my apartment on the same wifi. There wasn't an issue with this before. The furthest one from our router was showing lag when attempting to stream. I set out to find a solution to providing it with a stronger signal.

Goal: to get my chromecast connected to my 5ghz network


Attempt 1: I bought a media connector/bridge from Amazon. Linksys WUMC710. Crap reviews but I thought I could make it work. I also got the chromecast ethernet adapter. I got it set up with a dedicated IP and it worked great! No more lag. However, like others experienced, the media bridge repeatedly disconnected from the network due to periods of inactivity. This would require me to do a hard reset each time. So that option was out.

Attempt 2: Used my Netgear R6300 in bridge mode to the Netgear R7000 Nighthawk router. Set up for this was wonderfully easy and quick. its all set up and good to go. I plugged in the Chromecast ethernet into the router and attempted setup. I was able to get it set up fine, and the chromecast shows appears as a wired device on my router. However, I cannot seem to get any of my cast icons to find the Chromecast. They only show the other ones in the apartment. Internet is coming through the bridge fine. Plugging my laptop into the router acting as a bridge allows me to cast to the chromecast also connected to the router. So it seems it is somehow a separate network?
Please feel free to ask any questions. I'm just stumped.