My preferred daily use platform OS is EndeavourOS (on an Asus Vivobook).
There are no problems with other platforms and OS’s in our home, MacOS, iPadOS, iOS, Android OS.
I had to reformat my Linux set up due to other issues. Now I have no “WiFi” icon when I try to stream Youtube videos and when I am in the Brave browser, or Vivaldi browser, when I go to File, and on the down menu select Cast, I get a dialog box that states, in a dialog box “no devices found”. I am flummoxed and frustrated.
I actually tried to use mkchromecast but it didn’t work properly for me neither.
I also tried the built-in option in VLC but even if I could connect to chromecast it would load the first 10 seconds and after the streaming would stop.
The problem is the firewall.
You can solve it by moving the network connection from “public” to “home” via the “Firewall” GUI by going to:
Options - Change default zone