Thanks for the note here. Have you tried removing the app, restarting your phone, then adding the app back once more?
Please keep us posted. If that doesn't resolve the issue, please provide more specifics including the exact model of iPhone/iPad you are using, the version of iOS that is installed, and the version of the Roku mobile app you have installed.
Thanks for continuing to share your reports here.
Please provide the specific version of the Roku mobile app you have installed, along with the version of iOS that your phone is running, and the model of iOS device (if not already mentioned). We'd like to continue looking into these reports.