Could you please confirm if you have a Chromecast device? If yes, what generation do you have? Also, if possible, please try to install a Google Chrome browser on your Mac laptop and check if you'll be able to cast videos from it to your TV.
Just checking in to make sure that you've seen my response. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.