I agree with @aaiyar on it likely being a mesh issue. I have two of these locks literally 5ft from my hub and never have any issues with them locking or unlocking.
@aaiyar & @inetjnky - So, just move the hub closer to the lock? If "yes", would 15 feet and an exterior stucco wall be close enough? My old location hub location was about 25 feet and two thin interior walls. I don't have any other Z-Wave devices other than my door lock, so I don't believe I have a real "mesh".
@g.shepperd - Thanks, that's an excellent suggestion! I will do that, even if the C-8 hub move seems to fix the issue. (Funny thing, I do something similar with my cell phone's fingerprint sensor to get a higher recognition rate. I should have thought of this myself, but that's what this forum is all about!)
I can understand that you want the lock to lock if someone accidentally forgets to lock the lock. However, if family members think the lock is going to relock itself, they might become lazy and not bother to lock it manually. This is not a good situation.
Also if someone is going outside for a brief period, such as to water flowers, check the mail, etc. Having the lock relock automatically might not always be appropriate.
Hubitat is not designed to be a platform for home security, only home automation. Thus, be careful using Hubitat for any security-related task.
@rwclements228 - Yep, I agree. I know that Hubitat is for home automation, not security. However, when we have relatives and home guests that can't even follow the big freakin' "Lock Me when You Leave!" Post-It note on the door, it doesn't hurt to have a little backup in place. (Hmmm. Maybe I have some other issues here to deal with?)
Those locks are notorious (I have 3) you don't really have any sort of mesh. I would use a ring extender v2. They also have battery backup so that powering from mains to battery can be used as a trigger. Put it about halfway from between the lock and the hub.