ESP8266 and channel

Hi, we have some disconnection issue when we try, from smarthphone, to send SSID and psw to ESP (in SoftAP mode)... most of the time, as soon as the ESP connects to wifi, smartphone disconnect...

i found somewere that this shoould be a channel issue (ESP changes channel...)

Is anybody found a solution for this?

I noticed that the channel can be forced in both AP and BEGIN method... like

WiFi.softAP(("MY_TEST_" + serialNumber).c_str(), "", channel);

and

WiFi.begin(ssid, pass, channel);

is this the right approach?