Sorry for the issues you're having with your YouTube playlists. I'm sure that's frustrating and a bit confusing. Let's run through this and see how we can get things working fully for you.
First, we do have a checklist of things to look at, and you can find that here: https://bit.ly/3cv4Gtb.
After going through that list, if nothing there works for you or applies to your situation, let me know and we can look at other possible causes. Hopefully this helps you work out the issue, however. I look forward to hearing back.
I just wanted to check in real fast to see if you saw my reply and to find out if you still needed any help on this. If you're still needing assistance, please just let me know and I'll be happy to continue helping.