Hi there @Anipasz!
I'm here to help! :)
First of all I want you to do a fresh reinstallation of the Spotify App on your device by following this official step by step construction for 'Android'.
If you have Spotify Premium (you obviously do), bear in mind that when you reinstall the App all your offline available songs will be deleted and you have to download them again!
Please let me know when the reinstallation of the App doesn't solve your issue!
Keep It Up!