Hi there, I have been having this issue for a little while now. I am using a Oneplus 3 and for some reason when I have soundcloud playing the volume will reduce for a period of 1-2s before returning to normal when I am multi - tasking or if I lock my phone. I was wondering if I have got an issue with my settings but I am not sure what I am looking for. I hope someone can help. This issue doesn't seem to be resolved by going to silent, do not disturb or regular presets and I've looked through my settings and cannot see what might be causing this.