Thanks posting here in the Community! We'll gladly help you out.
We suggest that you try to post the playlist again, this time using a private or incognito browser. This way issues that may be caused by the data stored in your browser can be avoided.
If that still doesn't work you can upload a screenshot of what you're seeing when you try to upload a playlist to Facebook. That would help us out a lot in identifying the root cause of the problem. Just be sure to hide any personal or sensitive information. You can use the Insert Photos option in the post editor to do this.
Hope you find this useful. Keep us posted how you get on.
Have nice day!
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