Hi @Imagrest,
Thanks for the posts,
Try removing the channel from the Roku home screen by navigating to the channel tile, pressing the * key on your remote, and choosing 'Remove channel'. Then restart your device from Settings>System>System restart. Once your player starts up again, add the channel back once more.
Please note that Screen mirroring with a Roku device is not supported with iOS or Apple devices. However, we suggest checking Airplay: How do I use AirPlay and HomeKit with my Roku® streaming ...
Please let us know if there's anything else we can help you with.
Thanks,
Mary