Noob Q:Blinking track LED?

Hi all,
Just got an octatrack - wow!! What a machine.

I hope someone can help me with this: The LED next to track 7 is blinking non-stop, and the track won’t mute when I hit [FUNC]+[track button]. It just keeps playing. Also if press stop, and then start the pattern again with track 7 muted.
It’s the same behaviour if I switch to a different bank/pattern/part.

Please tell me this is some cool feature and not my unit being faulty.

Tried the manual, but couldn’t find an answer.

Peace

EDIT: oops…sorry for creating double-topic