Linked below is the Chromecast help center page.
Thanks providing our help center Cathal_S!
If you still need help with your Chromecast, please share more details on what's happening with your device so that we can provide you the appropriate steps.
I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.
Just bumping in to make sure that you've seen our responses. I'll be locking this thread if we won't hear back from you again in 24 hrs. Feel free to create a new one if you have more questions or have other concerns in the future.
Google Nest Help Center
Chromecast Help Center