Finally found a solution - this from Rokland.com
As you may have noticed, the latest Linux kernels have caused a large amount of wireless USB adapters to lose monitor mode support. Thanks to a diligent community of Wi-Fi enthusiasts a work around has already been found, so that you no longer have to downgrade to an older kernel.
You can find more detailed instructions on the driver install here:
GitHub - aircrack-ng/rtl8812au: RTL8812AU/21AU and RTL8814AU driver with monitor mode and frame injectionTested and working method as of AUG 2024.
If you have already attempted to install the driver first uninstall the driver. This can be done by opening Terminal and navigating to the directory the install was performed in. Then run the following command:
sudo make dkms_remove
Next we usually suggest making sure your distro is up to date.
sudo apt update && sudo apt upgrade
Next we will install some pre-requisites that are sometimes not included in every distribution of Linux by running the following commands in Terminal (*Note - This is mainly for Ubuntu users, Kali usually has these pre installed.)
sudo apt-get install dkms
sudo apt-get install make
sudo apt-get install iw
sudo apt-get install git
Finally we will download and install the driver.
git clone -b v5.6.4.2 GitHub - aircrack-ng/rtl8812au: RTL8812AU/21AU and RTL8814AU driver with monitor mode and frame injection
cd rtl*
sudo git checkout 63cf0b4
sudo make dkms_install
Hope that helps someone