My first time on this board. My issue was resolved. I have been using my 5G home base for three weeks and paid the first bill. This Saturday (09/25/2021), I was not able to use the external (first generation), Chromecast. I turn off all my devices first. Then I was able to resolve issue by turning off the Home Base 5G for one minute, then restarting it. I eliminate my devices first. Once 5G home base was restarted Chromecast started working.
To point out Every Saturday and Sunday the GEOLOCATION change. Monday through Friday is more stable locations. Use link to find my GEOLOCATION. https://www.iplocation.net/ .