Just to double check can you look over the information below:
--30 song playlist that is automatically added to your account and updated every Monday.
--The 30 songs are based on your listening history and the listening history of others with similar tastes to you.
--Only users who have been active in the last 30 days will get it. When they return and play some music, they’ll get it the following Monday.
--Only available after you’ve been with Spotify for two weeks.
--Added directly under New Playlist to your playlist listings.
--The playlist defaults to private. Users can set it to public.
--If they unfollow it, they can find it again in Browse or Discover.
The only thing I can think of that might have stopped DW's is if you have not used your account for awhile? Have you been using your account often? Also there should be an added date of the songs that were last added to the DW playlist can you post that date here please? Just also to double check, have you checked the webplayer here: https://play.spotify.com/ to see if the DW is showing new added songs to your DW playlist?
I have my premium account already about 1.5 years, and I listen over my phone almost every day. What is so weird is that the DWs playlist shows no new songs and displays that the current -old- songs have been added 3 days ago although the playlist is about 3-4 months old...!
Is it possible if I deleted the playlist or unfollowed it that this happens?
Not sure, is DW showing the same way on all devices like this, desktop app, phone app, and also webplayer?
You might try unfollowing the DW playlist and also log out of the Spotify app, then log back into the Spotify app, find the DW playlist again under Browse/Discover and follow it again and see if it updates correctly? If that does not work, I can escalate this thread and see if the community mods have any ideas of what to do next. The last resort is to try and do a clean reinstall of the Spotify apps in case of data file corruption.