Solution 1:

I found the solution here:

echo "options iwlwifi 11n_disable=1 wd_disable=1" | sudo tee /etc/modprobe.d/iwlwifi.conf

Reboot, and it works again.

Solution 2:

I recommend you to switch to iwd as a replacement for wpa_supplicant if WiFi speeds are important to you, as disabling 802.11n (as recommended in the other answer with the 11n_disable option) may cause a decrease in network performance in 2.4GHz networks that support 802.11n.

I got this to work on my HP Elitebook 1030 running Manjaro GNOME and am very glad I now get to profit from the entire WiFi bandwidth my home network provides. Before, disabling 802.11n was the only option I knew of. Here goes a little guide on how to get iwd up and running instead of wpa_supplicant.

Installation & Setup

Install the required package:

sudo dnf install iwd

Edit the NetworkManager config (I'm assuming you're running NetworkManager):

sudo nano /etc/NetworkManager/NetworkManager.conf
# https://iwd.wiki.kernel.org/networkmanager#nm_configuration
[device]
wifi.backend=iwd

The above config will make NetworkManager use iwd instead of wpa_supplicant which you're having problems with.

We now need to start/stop/restart the required services to get the config loaded and applied.

sudo systemctl stop wpa_supplicant.service
sudo systemctl stop NetworkManager.service
sudo systemctl start iwd
sudo systemctl restart NetworkManager.service

And to make your changes permanent (by having the correct service start on boot and without interfering with the wrong one):

sudo systemctl disable wpa_supplicant.service
sudo systemctl enable iwd

You should now be able to connect to WiFi networks using the normal GUI. If connecting that way doesn't work for you, try using the iwctl command line interface. Connecting to the correct network should work that way. To get an IP-Address assigned, you may need to run the command dhclient.

Refer to the Arch Wiki Link below to learn more about iwd and iwctl. Also refer to the Arch Wiki if you're having issues like getting your password (PSK) to work.

If you can connect to networks successfully, try removing the /etc/modprobe.d/iwlwifi.conf file to re-activate 802.11n on next boot / module reload. This was the point of switching to iwd, after all.

sudo rm /etc/modprobe.d/iwlwifi.conf

Sources

Steps taken from linux-whv.de, ArchWiki on iwd