Hello there!!! I want to ask you something about ALFA AWUS036AC. I installed the drivers in my Kali Linux, so everything should go well... but there is a problem
I want to put my ALFA in "mode monitor" so I write in a terminal:

root@kali:/home/usuario# ifconfig wlan1 down
root@kali:/home/usuario# iwconfig wlan1 mode monitor
Error for wireless request "Set Mode" (8B06) :
SET failed on device wlan1 ; Invalid argument.
root@kali:/home/usuario# ifconfig wlan1 up


I also use:

root@kali:/home/usuario# airmon-ng start wlan1
Found 5 processes that could cause trouble.
If airodump-ng, aireplay-ng or airtun-ng stops working after
a short period of time, you may want to kill (some of) them!

PID Name
494 NetworkManager
578 wpa_supplicant
612 dhclient
802 avahi-daemon
803 avahi-daemon

PHY Interface Driver Chipset

phy0 wlan0 rtl8192ce Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter (rev 01)
null wlan1 rtl8812au Realtek Semiconductor Corp. RTL8812AU 802.11a/b/g/n/ac WLAN Adapter
root@kali:/home/usuario# iwconfig wlan1
wlan1 unassociated Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency=2.412 GHz Access Point: Not-Associated
Sensitivity:0/0
Retryff RTS thrff Fragment thrff
Encryption keyff
Power Managementff
Link Quality:0 Signal level:0 Noise level:0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0


As you can see, I can't do nothing. What's the problem?