So i installed macchanger and it works manually but i also set it up in the installation to automatically change mac address when a network change is detected in a device and it does not work at all. I tried the official guide but it did not help. I use the latest ubuntu 18 LTS version. I reconnect with wifi but it does not give me a new mac address. I also tend to get same network IP even though i changed MAC on my home network (to which i have very limited access as it is dorm network). It might be because i am using a switch.