Auto Unlock failed

I am on my 4th u-bolt series locks (only because u-tec keeps sending me replacements). Each one has failed in one way or another. The first one and current one started out working fine, but then the Auto Unlock feature fails. The others before this one eventually failed preventing us from even using the keypad to enter. The keypad can still be used on the current lock, but the auto unlock feature has failed after 3 days with this current replacement. Tech support is in the process of now sending me number 5. There has to be an underlying issue causing this as clearly continuing to replace the locks is not solving the issue. I’ve tried resetting the locks, reinstalling them, but nothing seems to correct the issue. Has anyone else had this issue and have a solution?

@Mark2 Hi, Mark, we have contacted you in ticket#187916, please kindly check your e-mail.