Here is a simple solution to the network manager interference problem.
It was suggested by seen_bawl during the negative-one problems and MTeams have been using it ever since.
Leaving network manager running
airmon-ng start wlan0
ifconfig wlan0mon down
iwconfig wlan0mon mode monitor
ifconfig wlan0mon up
Now just run airodump-ng
This works for us
To put back in managed mode
airmon-ng stop wlan0mon
ifconfig wlan0 down
iwconfig wlan0 mode managed
ifconfig wlan0 up
Musket Teams