I encounter a problem with two or more ESP12F's with WiFi manager library on them (GitHub - tzapu/WiFiManager: ESP8266 WiFi Connection manager with web captive portal)
Let's say there are 2 of them On both is the same sketch with different client SSID. On both, I go through the procedure of inserting SSID, PASS, etc so they connect to a local WiFi network. If they are on some 2 meters, everything is ok. If they are on some 10cm, there is a problem
One of them connects to a local network. The other tries, but fails every time. When I separate them, reset them, everything is fine. Only if they are close. And I have one setup that needs two of them on 10 cm.