Hi there!

I'm having a big problem recently. I'm trying to build a mobile wifi pentester device using a Raspberry pi.
I have a pi 4 with 4GB ram.
Installed with StickyFingers-Kali-Pi-armhf-190703 (from https://re4son-kernel.com/re4son-pi-kernel/).

I bought an Alfa AWUS036ACH from Amazon.
When I'm using with airodump-ng I get poor results, and most of the time I get a message in the top line saying "interface wlan1 is down".
I have realtek-rtl88xxau-dkms (driver) installed.
What I mean about poor results: If I connect the card to a win10 machine, and click at the wireless thing in the taskbar, I get much more wireless network than when I use it in kali with airodump-ng.
I tried to boost up the tx-power to 30dbi from the basic 18, but it doesn't help anything.

My main surprise is that I also have a TP-LINK TL-WN722N (it is a lot smaller 2.4 GHZ adapter) and it's JUST WORKS.
Out of the box without any driver installed, or any extra work required.

I can attach a big (9dbi) antenna to it, and it work with that as well, without any tx-power magic or anything.
When scanning for networks it does NOT disconnect randomly like the alfa one.

Please send help to deal with that.