Background audio on after quitting

I’ve noticed after using an app (in this case Arturia iSEM) in IAA mode (AU mode seems to work properly), even after choosing “Background Audio” to be off, Cubasis 2 randomly displays the red “background audio on” stripe when closing Cubasis. Meaning sometimes it doesn’t quit background audio, sometimes it does. Force quitting Cubasis is then the only way to quit background audio, even after force quitting iSEM. This seems to be a change from Cubasis 1.

Is this the normal, preferred behavior of Cubasis 2? Is it buggy IAA? Is it buggy iSEM?