Sure, I'd be happy to help you understand some common YouTube playlist playback issues and how to troubleshoot them.

1. **Videos not playing**: This could be due to a number of reasons such as an unstable internet connection, outdated browser or app, or issues with the video itself. Try refreshing the page, updating your browser or app, or checking your internet connection.

2. **Playlist not in order**: If you find that your playlist is not playing in the order you set, make sure that you've selected the correct play order. You can change the order by going to the playlist settings.

3. **Playlist stops after a few videos**: This could be due to YouTube's autoplay feature being turned off. You can turn it on by clicking on the autoplay toggle on the video page.

4. **Private or deleted videos**: If a video in a playlist is private, deleted, or not available in your country, it will be skipped during playback.

5. **Ads interrupting playback**: Ads are a part of the YouTube experience, especially if you're using the free version. If you want an ad-free experience, you might consider subscribing to YouTube Premium.

6. **Playback quality**: The quality of video playback can depend on your internet speed. If you're experiencing low-quality playback, try lowering the video quality or check your internet connection.

Remember, if you're experiencing continuous issues, it might be helpful to clear your browser's cache and cookies, or try using a different browser or device. If none of these solutions work, you might need to contact YouTube support for further assistance.