Did you try adding multiple songs on the pc? It works fine for me.Maybe YTM was a mistake as well... I don't understand how every subsciption has features missing that seem pretty damn important. Like why can not I not easily remove a song from a playlist that is currently playing? You have to find the song in the actual playlist and delete it. Can't even search the playlist anywhere like w/ Spotify. And STILL no multiple selecting song. Want to add 10 songs from an album? Nope, you have to do the whole album or every song individually.
And why is there no option to remove all videos. I want music. Not videos. SIGH.