Volume fluctuates when changing apps or closing screen.

[user-removed]

Currently using Google Pixel 2 XL, the volume of a song will fluctuate back and forth while doing other activities on the phone eg. As soon as I start to type in the keyboard the volume will go quieter and if I stop typing it gets louder.

This happens with changing apps, locking or unlocking the screen and pretty much anything I do will affect the volume. This problem only started yesterday. I have everything up to date and it was working perfectly yesterday morning.

I have tried all the other recommendations on other posts but nothing is working.