(I know that I should have just used a mesh network)

I have a router from my ISP, and it is placed at one end of my house. My Chromecast, printer, and other IoT devices are connected to it. I recently connected another router via Powerline to the other end to get quicker speeds, and to get Ethernet for my PC. However, I can’t print off of the second router’s network, and I can’t use the Chromecast virtual remote. The router shows up as a single device on my ISP router, and none of my other devices connected to it show up.

Do I need to put the router in bridge mode, or do I just need to mess around with the configuration of it?
Will the router support 5GHz still? (My ISP router is only 2.4GHz) \

Second router model: Linksys EA6350