First of all, we recommend you to wait some hours before trying this method. It seems there's a delay between playlist creation with Soundiiz for YouTube and when the playlist appears on YouTube Music. It could take up to 24 hours before you are able to see created playlists on YouTube Music.
Also; double-check you have connected the right YouTube Music account to Soundiiz. For that, create a "test" playlist in your YouTube Music account with your YT App. Once done, connect your account YT Music on Soundiiz. You should see this playlist listed. If not, that means you didn't connect the right account (sub-account/brand account).
Finally, due to a recent change with the YouTube API, playlists created with Soundiiz to YouTube Music may not be displayed in the YouTube Music "Playlists" section (but only on the YouTube side).
However, you can still easily import your YouTube Playlists to YouTube Music following these steps:
- On Soundiiz, right-click on the YouTube Music playlist you are not able to see in YouTube Music interface.
- Select "Open on YouTube Music" (you will be redirected to the YouTube Music website and will see your playlist)
- On YouTube Music interface, select "..." and the option "Add to playlist" and "Create a new playlist"
- This time, your created playlist will be displayed under "Playlists" on YouTube Music
- (You can then delete the old playlist created originally by Soundiiz which is only viewable on YouTube and not YouTube Music)
Why have to do that? Since March 2021, Google has decided to not always merge (but could be a - delay - thing) YouTube and YouTube Music playlists anymore (and the same for channel subscriptions/artists). However, as Google is not proposing a YouTube Music API, Soundiiz can only use the YouTube API. And so, we are not able to created YouTube Music playlists but YouTube-only playlists.