There is a caching mechanism in the backend server after retrieving playlist from YouTube, in order to reduce the process burden, and wrong operations from the user (e.g. click shuffle many times by chance). The caching time is 60 sec at minimum, and can be length_of_list * 0.3 second at maximum. So after you shuffle a playlist of 10K videos, and you do some updates to your list, you have to wait about 3000 second for the cache to expire.
Currently, YouTube senses update through thumbnail video for the list. So after the playlist is updated, choose a different video as the new thumbnail, i.e., click the 3 dots on the right side of the video and choose “Set as playlist thumbnail“.
Some browser extersions (certain Ad-blockers, VPNs) can cause the player malfunction, e.g. preventing the browser to send necessary info to the backend server. If you get such a error alert, turn off some extersions and try again.
You can bookmark playlist by adding query parameter after the URL, such as:
After playlist is shuffled successfully (ID is verified), the bookmark button is enabled and when clicked, a new tab is opened with the link and playlist id, for you to bookmark it without having to manually compose the link.
As the bookmark button enabled, the autostart checkbox is also enabled. If you check it, the generated link with have the autostart parameter with it. Refer to next question.
You can let the playlist start automatically, by adding query parameter &autostart after the playlist id. In addition, you can choose background color by adding query parameter &bgcolor=<color_name_or_code>. Refer to HTML color.
You can only shuffle at most 10 playlists together, those after 10 will be ignored. Also make sure each playlist ID is valid, invalid ID may render the ID(s) after it useless.
First, set Chrome to be Not optimized for Battery, refer to Recommended Answer in this link, you might need to restart your phone. Second, After you start this player in Chrome and return to desktop, the player stops but audio control panel will appears in the notification area. Click the play button there, the player will continue play in background, even when you lock the phone.
When returning to this site, you can pick up where you left by clicking "Resume Last Session" button.
clicking "Show Playlist History" button, you can see all the playlists (title and ID) that has been shuffled successfully (latest first), you can select the list(s) again by clciking the corresponding entries in the history list (multiple lists case is also supported).
Three accompany Chrome extensions to this webpage are made to help you to navigate your YouTube playlist, even if the videos are played in non-active tab, PIP (Picture in Picture) mode. Go to PIP extensions to know them.