Spotify 'forgets' that shuffle is turned on

[ichmagkekse94]

Plan

Premium

Country

 Germany

Device

JBL Playlist

When I start a playlist on shuffle on my JBL Playlist  (with built-in Chromecast) the shuffle option resets (the sign is still green though) but it either starts over with the last added song I added to the playlist and continues like shuffle is turned off or it immediatly behaves like shuffle is turned off and just plays the next song (the one below the one playing right now).

This just happens on my JBL and JBL assured me that the issue isn't coming from them.

It also makes no difference from which device I'm casting (Windows 10 PC, Android 8.1).