I'm trying to add some new notification sounds to my pixel 2 XL and it just refuses to pick them up. I've placed the MP3s in DCIM/Media/Notifications and they just don't show up. Google search tells me to use a secondary file explorer to select them but I made the mistake a while back and told it to use the default one always and can't seem to figure out how to reverse that decision. Is there some trick? I've tried shutting down/restarting and no go. My custom ring tones showed up fine, but notifications.. nothing.