This typically is an indication of directional communications issues with the lock. Either the lock has lost one way communication with the hub or the response packets are being lost in the mesh. Some z-wave module are more susceptible to this (esp some CT thermostats, but they have an easy fix to reset the device without having to re-pair them).
If it’s the former, you can try to disconnect the batteries and reconnect them. If that doesn’t work then you’ll have to re-pair the lock with the hub.
If it’s the latter you should add a buffering device between the lock and the hub as explained here (it never hurts to do this anyways).