RTL8812AU driver listed in lsmod, but not working
Sebastian Wright 
I have a TP-Link Archer T2U Plus USB WiFi adapter that has the Realtek RTL8821AU chipset. The driver isn't preinstalled on Ubuntu 20.04.3 (kernel 5.11.0-27-generic, if it is preinstalled on 21.10 or 20.04.4, please let me know and I will upgrade) so I had to manually install the driver. I found one in the universe () that's made for the RTL8812AU, but it also works for RTL8821AU, because there is RTL8821AU written in the /os_dep/linux/usb_intf.c file.
I installed it with sudo apt install rtl8812au-dkms, however, the driver doesn't work, because TP-Link Archer T2U Plus's ID isn't listed in the /os_dep/linux/usb_intf.c file. So I downloaded the source code of the driver (using apt download rtl8812au-dkms), unzipped the .deb file, got the ID from the lsusb command (it's 2357:0120) and added a line
{USB_DEVICE(0x2357, 0x0120), .driver_info = RTL8821}, /* TP Link - T2U Plus */under #ifdef CONFIG_RTL8821A in the usb_intf.c file.
Then I compiled the source code with make and sudo make install and restarted my PC and the driver doesn't work. It is loaded, because it's showing in lsmod everytime I plug my WiFi adapter, but in lsmod it's saying used by: 0.
I am sure the driver works with the RTL8821AU chipset and I am sure Archer T2U Plus is using this chipset, but it doesn't seem to work. I think the problem is that I installed it wrong, or that the 8812au module showing up in lsmod is another module (that I had tried before trying this package from the universe, because I had tried a lot of different drivers before trying this one) and the old module is handling the WiFi adapter instead of the rtl8812au-dkms package from the universe (compiled from source code with the edited usb_intf.c file).
I tried to run sudo depmod -a and sudo modprobe 8812au before restarting my PC, I also tried to install it while the adapter was unplugged and plugging it after a reboot, I tried using USB 3.0 ports on my case, USB 2.0 and 3.0 on my motherboard, nothing worked.
Can you please guide me step-by-step on how to compile and install the driver after I edited the source code or how to see if the module really is the one with the edited usb_intf.c file (I am new to Linux)?
BTW the driver has dkms, but because I installed it using sudo make install it isn't showing up in the dkms status. Also, after installing the driver the WiFi adapter isn't showing up in nmcli device or lshw -C network, only in lsusb and the module in lsmod.
