when you put your spotify likes on shuffle, it's not actually shuffling all of your liked music, but rather the music you have listened to the most frequently in the recent past. if you've ever felt like you've been hearing the same music whenever you're on shuffle, you're not crazy, this algorithmic influence is likely why.
despite users constantly requesting a true shuffle feature on spotify, the company has stated numerous times that they have no intent on changing their current shuffle options.
to bypass this lack of effort on spotify's behalf, i found this app that connects to your spotify and actually shuffles your likes and other playlists with no bias. it's been really refreshing to truly listen to all of my likes and not just the top 50 most listened-to tracks on my spotify.