I have found a solution to this issue that works for my AC1200 dual band card, with packet injection support and monitor mode working. I would strongly suggest you check your chipset and make sure that it is compatible (mine is a BrosTrend AC1200 dual band V2 card) before attempting this. I used this driver from cilynx on GH. I clone the repository and built the driver from source. The precompiled debian packages never fully installed a gave me a dkms error when adding the module to the kernel headers. After building from source, I restarted and left the card plugged into my laptop, and it was recognized by Kali with full support like an Alfa card.
To build the driver from source is not a scary task. First you'll need to make sure you have the dependencies installed before you build. Then you'll have to locate your source code folder, build your driver and install it. Open a terminal and type:
sudo apt-get install build-essential build-dep
cd /your/source-code/folder
make
sudo make installAfter this, your driver should be installed and to ensure proper function, I suggest restarting and leaving the wifi adapter plugged in on reboot so that it is recognized and configured correctly.
Time is precious. Waste it wisely.
Just because something is illegal, doesn't make it wrong. Just because something is legal, doesn't make it right.