How to stop MAC address from changing after disconnecting? linux

Network-Manager will reset your mac address during the wifi scanning.

To permanently change your mac address:

Edit your /etc/NetworkManager/NetworkManager.conf as follows:

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

[device]
wifi.scan-rand-mac-address=no

[keyfile]

Edit your /etc/network/interfaces by adding the following line:

pre-up ifconfig wlp68s0b1 hw ether xx:xx:xx:yy:yy:yy

The xx:xx:xx:yy:yy:yy is the new mac address obtained from the output of macchanger -A wlp68s0b1

sources: click here

wiklinux