Can't download playlists suddenly

[Sim66]

Plan

Premium

Country

UK

Device

Samsung S10

Operating System

Android Oreo

My Question or Issue

This is something that's just started happening.  On my phone (Samsung S10) if I try to download a playlist I just get a message "You discovered a Premium Feature!  Get Premium".  I *am* Premium, as it confirms if I look at my Account settings (just confirmed that on the desktop as well).  Any ideas?  I use my phone to run a music quiz in a pub that has no wi-fi, so as you can imagine not being able to download playlists is a bit of an issue...