It is unfair to question the Kiox itself when as far as I know IT is functioning just fine. If you look at the reviews of the eBike Connect app though, it has not been well received. It has some trouble tracking rides that I have seen in just three days of use. I believe that the most current version is a step back from a mediocre rating that it had prior to the update.
My concern is IF the app has anything to do with how locking works, then it may have issues with locking reliability.
I wouldn't have any reservations about upgrading to the Kiox.