I have four 914’s. They only need to be close (inches) to the hub when you do the inclusion step. My back door lock had some similar, if not worse, issues the first couple days. I replaced the batteries, took the main mechanism out and noticed that the z-wave board or battery connection appeared loose or something. The button to exclude/include wouldn’t light up sometimes when pressed. I just kind of pushed around with my thumb which seemed to move some of the plastic casing in place. The lock has since worked perfectly for a couple months now. The quality of Kwikset just isn’t great at all. This was one of the two 914’s I got from Home Controls Inc. The other one was dead on arrival and replaced but I had to pay shipping. The two that came directly from Amazon worked just fine and didn’t have as much sharpie pen writing and sticker residue on the inside parts.
I also did a hub z-wave network repair and many more since when new devices are added. I assume you tried that already.