See my previous posts in this thread for the history. I received the replacement Wall Connector and found it had the same problem; however, i found out that if the WiFi that successfully provisioned the unit on the first configuration attempt is turned OFF allows connection to the WC local configuration SSID again and enables the button on the wand. This does not fix the problem but it does allow access to WC local WiFi SSID again. The problem seems to be a timing problem with the DHCP handshake protocol between my router and the Gen 3 WC and not signal level etc. In the failed mode the WC appears to ask for an IP address as the lease time is reset on the router but the status shown is offline. My Linksys Model WRT3200ACM router has worked with every WiFi device used to date except for this WC. The router has the latest manufacture supplied firmware installed that it had when I purchased it 3 years ago. Tesla indicated a later firmware update would hopefully fix this problem. In my opinion, the WC should never get in a state where local access is not possible. Fortunately, I decided to try turning off the 2.4G radio on my router or the problem would still exist.
Hope this information helps someone!
Sorry, an update though I had already done so. I connected the WC to my a network extender/bridge and it has worked flawlessly since. I found a Roku model that seems to have a similar DHCP issue. Wish my fairly high end router would let me age out DHCP leases instead of requiring a factory reset. Most of my previous routers had that feature.