Hi,
I've Mi Mix 2 with 8.3.1 Oreo version and after update (i came from 8.2.1 Oreo) *no-support-for-this-app-on-this-forum* not working for me. In the precedent version (8.2.1) it works but slowmotion (I've installed Arnova version v6). I've Magisk and the module with camera2api and slow motion abilited.
It's normal...