Smart shuffle doesn't work properly

[JCHHCJ]

Plan

Premium

Country

UK

Device

iPhone 14&desktop Dell

Operating System

(iOS 16, Windows 11)

My Question or Issue

Smart Shuffle doesn't work. The songs I add to my main playlist from the desktop app are not added on my iPhone App, and after added to playlist, they still are displayed within the playlist with + and - signs (to keep or remove from playlist). And the same happens when I add a song on the App - it doesn't synchronise with the desktop version. Also, in terms of display - when I add a song from smart shuffle on my App, the green icon disappears, while it doesn't when the song is added on the desktop. The option on my playlist are also misleading - the + sign does not actually save songs into the playlist in which they are suggested via smart shuffle as they are saved into... liked songs while the - sign does remove this suggestion from the playlist! Why on earth is this the case? And shuffle is completely broken as it suggests the same songs over and over, skipping has no effects whatsoever, and sometime I have to skip 50+ songs to listen to something different. Randomization doesn't work and has never truly worked. I will stop here, but there are so many other issues QoL issues that I would fill more than one page of complaints.