1. When the wireless WiFi network icon does not appear on the iPhone, it will be displayed even if the wireless network is turned off and then turned on in [Settings - Wireless LAN].
2, similarly, after turning off the wireless function of the control center, turning it on again will not solve the problem.
3. The only way to fix the problem is to reboot the iPhone6s. Press the power button on the right side of your iPhone to display the shutdown option.
4, when the shutdown option appears, slide it out again, and then press the power button again to turn it on, you can solve the problem of not showing the WiFi icon.