AT+CWJAP:3 FAIL

[Breixo]

Hi to all,
We have a design working properly with an ESP-01S, its current mission is to capture the current date and time.
We intend to replace the ESP-01S with an ESP-12F for future features, however, in testing with a pair of ESP-12Fs, we get this:

ATE0
0K
AT
OK
AT+CWMODE=1
OK
AT+CWQAP
OK
WIFI DISCONNECT
AT+CWJAP="ssid","password"
FAIL
+CWJAP:3

The expected response should be:
WIFI CONNECTED
WIFI GOT IP


The version of both ESP-12F is:

AT version:1.3.0.0(Jul 14 2016 18:54:01)
SDK version:2.0.0(5a875ba)
v1.0.0.3
Tue 13 2018 09:37:06

Please, any suggestions?