esp8266 stuck in wifi3 802.11g

[Jack-Willder]

hi guys, i live in a relatively large house and my router doesn't cover the entire area so i searched for an solution and ended up here with a esp8266 with your bin files loaded and working fine, but, it started using wifi 3 802.11g instead of wifi 4 802.11n, i want to know is there any reasons for this behaviour?