Do you have the SmartView button in the Quick Settings section of the notification shade? Tap it, select the TV from the list of destinations available, use the TV remote to select to allow the casting. I just tested this with my Insignia Roku TV and Samsung Tab S7.
@B. Diddy beat me, because I was testing it!
If you need additional help or have more questions or details to share, please join the site so you can reply in this thread. See
this link for instructions on how to join Android Central.