Sound quality issue with spotify premium

[Vique]

Hi,
Having spotify premium, I am facing very bad sound quality, like if the band is playing in a closed bathroom. The issue comes and goes apparently without any reason. I haven't found and fix to this despite having searched the web and despite it seems lots of users are facing same issue. Note that the sound quality is fine with other apps.
My device is oneplus one, Android 6.0.1 cyanogen elderberry (5). My APG headphones are ok.
Yes, I have tried to reboot the device, clear app data, clear app cache, uninstall and reinstall spotify, etc. Nothing works. The audio FX is off.
It's really frustrating paying for such an awful sound quality. Please help to get a fix or I will close my premium account.
Thanks.

[Joe]

I would suggest you get in touch with spotify direct but I don't think they support phones with custom ROMs.

Have you tried reinstalling spotify, following the steps here?