Unliked songs/albums reappear in library

[SynnoNym]

Plan

Premium

Country

Germany

Device

Pixel 3, Desktop, Spotify Web Player in Chrome

Operating System

Android 9, Windows 10

My Question or Issue

I have noticed a strange behaviour of my spotify: if i like a song/album with the heart and "unlike" it - for example - a few days later, sometimes the song/album keeps reappearing in the library after a day or so. Am i the only one with this problem? It seems that it does not matter, if i "unlike" it on my mobile device or the desktop client or the web player...