New music mix
My Apple new music mix not updating more than a month.
iPhone 11 Pro, iOS 13
First, I'd suggest restarting your iPhone.
If that doesn't help:
Try signing out of your iTunes and App Store account and sign back in. To do this, go to Settings > iTunes and App Store > Tap on your Apple ID > Sign out and then sign back in. This will remove any downloaded music you have and you will have to redownload the music.
If that still doesn't help:
Contact Apple Support: Get Support