The driver however, did not work until I ran a script called remove-driver.sh from the driver that I used to use (https://github.com/morrownr/8821cu-20210916). Then the wifi adapter started working again :)
Thanks a lot for the help - I am still not really sure what the problem actually was, but I'm very thankful for having my internet connection back :)
//Original post below:
Hey :)
I've been using a wifi adapter for my computer for about a year. A few days ago, it suddenly stopped working. It no longer shows up when I run 'nmcli device' in the terminal. When running 'lsusb' it still shows up as 'Realtek Semiconductor Corp. 802.11ac NIC'.
To my knowledge I hadn't updated anything before it stopped working. After it had stopped working, I used usb-tethering from my phone to do a system update, hoping it would fix the problem. I think one of the updates was a linux firmware update. Anyways, it didn't fix anything.
The adapter didn't work out of the box. It arrived with a driver called 'RTL88x2BU' and a document stating that it was compatible with the following chip drivers for linux:
RTL8811AU
RTL8811CU
RTL8812BU
RTL8814AU
I couldn't get the driver it arrived with to work, so instead I downloaded this driver and have been using it until it stopped working. https://github.com/morrownr/8821cu-20210916
this driver only states that it supports some linux kernel version. I'm using '6.8.0-40-generic', which it does not claim to suppport. I download this driver, which should support my kernel, but it didn̈́'t work either. https://github.com/morrownr/8821au-20210708
I've tried running lsmod on my system, and it seems to be, that no wifi driver even starts. The only thing I can remember doing just prior to my internet not working, was running 'systemctl disable jellyfin.service'. I doubt that has anything to do with this, but I'm not sure what else it could be. My only other theory is, maybe the usb wifi adapter hardware just gave up.
I know the issue has be fixed but this is something you (or others) might want to consider.
If you have a desktop computer you can get a "wireless access point" which you can connect to your desktop using an ethernet cable then connect the AP to your WiFi network.
This negates the need to find an adapter that supports Linux and having to install drivers to make an adapter work.
With an AP the computer only sees an ethernet connection and as the AP is separate to your computer you can position it where it gets the best reception (there are even access points from the likes of TP-Link and others that can use POE (power over ethernet) so you can run just one cable).
Wireless access points are really versatile and can be used is a number of ways.
I recently upgraded from an all in one WiFi router to a wired only router (I have fibre) which is then connected to my desktop using ethernet and I have a UFO style access point on the ceiling connected using ethernet and powered by POE.
If I need to upgrade the WiFi at a later date I don't have to redo my entire network setup.
Are the networking service and network manager up and running? systemctl status networking systemctl status network-manager
What does rfkill list wifi show?