Unable to remove song from "songs"

[Mariiius]

I removed all of my songs from "songs" playlist. I am unable to remove two songs from playlist. Once of them is greyed out and pushing the little "check" button (which becomes "x" button when mouse is on it) does nothing.

The other song is not greyed out and removing it does nothing as well. Interestingly, when I try to remove it it says that it was removed successfully and then I can add it again. By doing so, I have two same songs in my "songs" playlist.

In web player everything is fine - those two songs are not being displayed (and my "songs" playlist is fully empty)

In android app those two songs are displayed and I am unable to remove them from android app aswell.

Here is my question: how to completely remove all of my saved songs from my account?