Device disappeared when change wifi mode using airmon-ng

[urmsm]

I use command "sudo airmon-ng start wlan0" to change wlan0 to different mode,and the device gone in the net speed panel.But when i change it back using "sudo airmon-ng stop wlan0mon",the panel still empty.I treated it as a bug.No father investigation.

[hedayaty]

could you provide the output of the following command:

cat /proc/net/dev