Hi @Emk74,
Welcome to the Roku Community!
We understand you're having a problem with the screen mirroring on your Roku TV. We're happy to assist you. Please try to restart your Roku TV by going to settings, system, power, and system restart. After restarting your Roku TV, you may need to restart your phone and try to see if the problem still exists.
Let us know how it works.
Best regards,
John
John
Roku Community Moderator