I found a minor bug with the DJI Go 4 version 4.3.4 on my phone Huawei P20 Pro.
When i change the option Style for video, in my case a CUSTOM style, my selection is saved and correctly displayed.
However if i turn off my aircraft DJI Mavic 2 Zoom, close the DJI Go 4 app. Then relaunch the DJI Go 4 app and then turn on my aircraft, then go back to the option Style for video, my initial selection has been forgotten by the app and it will display NONE instead.
The good news is that the camera actually seems to still use my initial settings but the information does not seem to be transmitted correctly to app in order to display the correct selection for the option Style.