I purchased the Wyze lock specifically for the auto-unlock feature. It has never worked reliably, After a couple of frustrating months working with Wyze, and told to reread the instructions, which I had already memorized, I spent some time researching and I have some information concerning the iPhone. I am assuming that Wyze uses the phones MAC address for identification. On an iPhone running IOS 14+, by default the iPhone has MAC addresses set to using private address. With IOS 14+, to improve privacy and tracking, each wifi SSID uses a different MAC address (cell, home, public) and in addition, the MAC address automatically changes every 24 hours. This seems to create a situation where you can leave the house on the wifi MAC and then return on the cell MAC and the lock will not respond, since the phone will have a different MAC address. Also, we use the Mint cell service which switches to VOIP at home, then to cell at the end of the drive, just to make it more complicated. Sometimes the auto-unlock would work, most times it would not. There is a setting on the iPhone to disable the private MAC address feature, so that the phone will always report the same MAC. I changed this a week ago and at least for now the Wyze Lock has worked each time. If you are having an issue on an iPhone, try disabling private networks.