NetworkManager is normally good for GUI users who may not be good with manually confguring devices, but if you are using things like bridging and bonding, it will often break things.
systemctl disable NetworkManager
Now that it's disabled you will need to stop NetworkManager. NetworkManager will still be running until you reboot next or manually stop it.
systemctl stop NetworkManager
After that NetworkManager will be disabled and stopped. If you ever need to re-enable it, you can do the opposite:
systemctl enable NetworkManager
systemctl start NetworkManager