so I got alfa awus036ach wifi adapter I have put the monitor mode on and every time i try to run airodump-ng on a particular bssid I get interface wlan0 down also when I use airmon-ng check kill I get one of the two bugs fixed interface 1 or no client showing up
but I can easily get .cap file using fluxion even I select aircrack-ng option in fluxion

so what is the problem