The queue in the YouTube Music web client is now saved after closing and restarting tabs, and is also loaded from a smartphone, 9to5Google reports.
Google started testing this feature on the web version of YouTube Music in May 2024, but turned it off a few weeks later. It so happened that closing the music.youtube.com tab would reset the mini-player and the Up Next queue. Now the website remembers what you were listening to last when you restart. This applies when you are in the middle of playlists or albums.
By the way, this is especially useful if you return to your desktop after listening to music on your smartphone.
To test if this works for you live, turn off the queue on both clients and start playing something from your smartphone (Android or iOS). After that, open music.youtube.com. The mini-player should already be full.