03-26-2019 11:08 AM
What resolution setting are you using for video recording? If you're seeing 'Preview Not Supported' or a 'Camera Busy' message appear, this means that the resolutions and/or fps is too high to be supported by Live Preview.
In addition to this, Time Lapse Video, Night Lapse and Burst Mode is not supported by live preview.
You can refer to this article for more information about Live Preview While Recording In The GoPro App.
Hopefully this helps!