On my Helix LT, the 1 switch looper acts very weird sometimes. I don't even know how to explain it, it just doesn't operate as it should. It's playing, I hit the footswitch to overdub, nothing happens. I stop it, long press to delete, and it starts playing again. I think I've even had it spontaneously start recording without having pressed the FS. To reset, I usually just switch to a preset without the looper and then switch back, but I never had this before 3.01.
That's my beef. I did see something about an update for the 1 switch looper in HXFX. maybe it's the same.
Posted this in bug reports already.