I know this is an old thread, and still an issue in C7, but after experimenting with “New/Stacked” I think I can clear up the way it works (but it’s still not exactly desirable). Then the next person who searches for this won’t be so confused. just a little mad.
It only mutes each previous take when they’ve all been recorded during a single cycle loop session. To make it work correctly - remove all takes and start with a clean track. Then start a cycle loop in record mode and each previous take will be muted, as advertised.
But once you stop recording, then go back and start a new looping session on that track, all previous take(s) will only be muted if you manually solo the current lane. Unfortunately also - there is not a mute button on the lanes, only solo buttons, which is really odd and inconvenient to me? There must be a technical reason that this is more desirable, but I can’t figure it out. Once I get to this point, if I have takes I want to save but not hear, I’ll move them to another track for awhile. I still think it should not play them.
jaslan suggested that it’s good to have the option to hear each previous take - that is a different option, you don’t use Stacked, you use a different record type: “Mix-Stacked (no mute)” which does exactly what he said. New/Stacked should work as advertised whether or not you’re going back to previous material and it doesn’t.
 - wait, there’s a mute TOOL? I never realized that was there - I guess I never really needed it until I started doing tons of lane stacking like this particular style of playing requires. That does help matters a little.