Favourites Mix is based on old listening preferences
I have had this issue now for over 2 years. My weekly favourites mix is not updating to my new preferences. It still thinks my favorite artists are XXXTENTACION from 2018 and Juice world from 2019. I do get some of my new songs too sometimes but 70-90% of the list is always songs that I used to listen too back in 2018 to 2021.
This problem occurs on all devices, there since the weekly playlist is synced on all devices.