Unable to arrange songs in a playlist created by me

[Scpva7]

Plan

Premium

Operating System

Windows 10 laptop

Issue

I am unable to arrange songs in a specific playlist created by me, however, I can arrange songs in other playlists created by me using the exact same account.

I've restarted the laptop Spotify app, and the problem still remains. 
I was able to arrange songs in this playlist until a few days ago.

please assist.

[Scpva7]

update: the issue was caused because I clicked on sort by Artist. 

It turns out that when you sort the playlist by one of the filters you cannot move the tracks up/downs. So you will need to untick the filter that it's sorted by and then it will work.