"S" Mode Has Jittery/Flickering Exposure for Video

I’ve been wanting to use “S” mode, or Shutter Priority mode, to shoot video, but I noticed there’s this really annoying flickering that occurs while the camera is adjusting exposure.

I thought it was just my phone screen at first, but then I recorded a video shooting in “A” mode and then the same scenario in “S” mode and overlayed the waveform from DaVinci Resolve and it’s clear to see the exposure flickering up and down while the video plays back.

My goal is to slap on an ND filter and utilize the “S” mode to help make vlogging easier and more convenient, but this is rendering my videos unusable. I’m not sure why this is happening. I have seen a video in the past that mentioned something to the affect of iPhone’s having different white points at different ISO values?, but again I’m not sure if this is due to the iPhone itself, or if it’s something under the hood that needs to be tweaked on the Apps end.

The Moment Pro II App is the only camera app that I’ve used that has a shutter priority mode so I’m not sure if this is a common problem for developers.

Any help or suggestions is appreciated! Thank you for your continued work in making this a great app!