Sounds silly, but did you try different cables and make sure they are pluged in well? I had a pedal that I thought died. It ended up the cable wasn't pushed in quite far enough. I have also had problems with cable shorts and stuff. Otherwise it might just be a wire that came loose inside it.
Try the pedal all by itself just to make sure it's really that pedal and try different cables while the other pedals are unplugged from it as suggested.
Since it happens in bypass, I'm guessing it probably isn't a loose wire.
It MAY be a loose wire but if it only happens in bypass, I doubt it. Sounds like an issue with the flip-flop switching and/or it's JFET transistors. Might just be a loose component.
It really couldn't be the switch or jacks. It seems to work fine when engaged.
The switch is just a momentary switch so it wouldn't work just one way and not the other. It doesn't have an alternate state.
If it was the jacks, it wouldn't work in both bypass AND when engaged.
