You have the option to remove the video play-bar on your videos.
Videos uploaded to your Thinkific site are hosted with Wistia. Unfortunately, due to limitations of iOS, when a video is viewed in fullscreen, mobile devices do not allow you to use the Wistia video player and instead use their own native mobile player which will display a play-bar.
We understand that this is not ideal in some cases. Please don't hesitate to contact the Support team to provide feedback.