Instrument track mute strangeness

[musicman691]

While working on a synth version of the William Tell Overture I had some instrument tracks muted while working on a single track. I wanted to unmute all the muted tracks at once so I did my usual thing of holding down the option key and clicking on the Mute button in a single track. ordinarily that would unmute all the muted tracks. For some reason it didn't and I tried different combinations of things but nothing worked so I manually unmuted each track separately.

Hit the spacebar to play and there's no audio but if I play my MIDI keyboard on a highlighted track I hear notes. So I figure let me show instruments view in the edit screen. Lo and behold the mute button there for each track showed the tracks being muted. As I understand it this just mutes the MIDI on the track right? Shouldn't also the mute icon in the control panel also show something's muted? I don't remember what key combo I hit to do that and can't seem to find anything in the PT manual or shortcuts guide.

PT11.3.2 on OSX 10.10.5