Aperture value often override at F2.8, having set M in DJI App

Hi Zane,

I often set M mode and my own value exposure (eg. F4, 1/800 and iso 100) in the DJI App before going to Map pilot. There I select M and set same shutter in pilot, but my flights images come with a F2.8 aperture value. Is this a set value in Map pilot? Anyway to override it? Thanks