Apple Music not syncing Library or Playlists with web player, rekordbox, and Serato DJ Pro

I have just subscribed to Apple Music in order to use it for DJing with either rekordbox, or serato DJ pro, which both support Apple Music streaming. I created some playlists in the Music app on my Mac (15.5 (24F74)), and they sync fine with the Apple Music app on my phone. However, they don't appear in rekordbox, serato, or the web player (https://music.apple.com/). If I create a playlist on the web player then it immediately syncs to my Mac and phone, but as soon as I refresh the web page it's gone. Seems to be the same for the entire library (albums, songs etc).