Hello - I'm a Premium User in the US with an iPhone 11 Pro with iOS 14.2
Lately I've noticed that the Shuffling isn't truly working. It will shuffle but a ~10 song subset of the songs of a much larger playlist are always at the top (vs. truly randomizing the playlist).
Please see the attached screenshots where I've done this a few times on the app created playlist that has 150 songs. However, this is not unique to this playlist and has been a recurring issue for me. I've also noticed this on both the iPhone app and the desktop computer app.