Both have the same label:
MODEL: ESP8266MOD
VENDOR: AI-THINKER
I have a testprogram making GPIO9 as an output blinking a LED.
One modul is working as expected. LED is blinking at the right pin.
The other one is not working on GPIO9.
Is it possible, that there are different editions of the ESP-12E available?
I have read somewhere, that GPIO9 and GPIO10 are only working on a ESP-12D. But GPIO10 is working on both.
If not, than the conclusion would be, that the pin of the module is faulty.
ESP8266 Arduino add-on
Arduino IDE 1.6.5