I've also experienced the infinite sync bug. I've noticed it gets stuck on "checking for updates", so maybe Kobo's servers just aren't sure how to respond or something.
More amusingly, since updating my Kobo has upped my total reading time on this device from around 20-ish hours to 496.
I absolutely love the Aura One, but my goodness, people here aren't kidding about the firmware being flighty
