Update Reproduced the same case without application. Just switch in iOS wifi settings between Home Wifi and Device wifi. Once per 5 switches, Device Wifi display a message as on screenshot and connecting need more than 2 minutes, in other cases immediately (4 seconds)

Hello Matt Eaton Thanks for your advice. I have reproduced this issue without my IoT device, switched between 2 office routers (from iPhone settings app, my app was removed). The result was the same, sometimes the connection needs 2 minutes to get an IP address. I have run a wifi profile on iOS, and see the same delay. This is info from the profile: 12:23:56.694 Attempting to join WPA network: XXXXXXXX 12:23:57.041 __WiFiLQAMgrSetCurrentNetwork: Joined SSID: XXXXXXXX BSSID: xx:xx:xx:xx:xx:xx RSSI: -32 Chan: 6 ApEnv: Learning(1) RSSI: -32 Chan: 6 ApEnv: Learning(1) 12:26:05.752 {AUTOJOIN-} __WiFiDeviceManagerRouterIpv4Callback: ip address configuration completed for XXXXXXXX Reboot device or reset networking settings helps for the first few hours, then the issue is reproducible again. Use waitsForConnectivity, in this case, is not a good solution, because 2 minutes is too much for waiting. I can't reproduce this issue on iPhoneXMax (iOS 14.2).

vadzimfrombelin I have created a TSI ticket only today. Feb 01. 2020. Didn't have time to do it before.