Ubuntu 20.04 wi-fi not working

Diagnosis

Please post the output of

$ lspci -nnk | grep -i -A2 net
$ ip a
$ sudo ip link set wlp2s0 up
$ ethtool -i wlp2s0
$ service network-manager status
$ uname -a
$ ls -al /etc/modprobe.d
$ cat /etc/modprobe.d/modprobe.conf
$ cat /etc/modprobe.d/iwlwifi.conf
$ cat /proc/cmdline
$ modinfo iwlwifi
$ ls -al $(locate rfkill | grep service)

EDIT

$ dmesg | grep phy0

Plus, you can install hardinfo and inspect Computer -> Kernel Modules, Devices -> PCI Devices, Network -> Interfaces -> wlp2s0.

I wouldn't think this relates to the kernel version, as some reported in old posts.

Possible solutions

Try:

1. Disabling Secure Boot/Fast Boot in BIOS (source) and Fast Startup in Win 10 if possible (source).
2. sudo rfkill unblock all (source).

EDIT

3. This and this show options to be placed in a suitable /etc/modprobe.d/ file, maybe rfkill.conf. I am not sure which apply to iwlwifi. I would try adding

   options rfkill master_switch_mode=1
   options rfkill default_state=0
   

   to file /etc/modprobe.d/rfkill.conf and rebooting.

4. This post in an old thread for slackware shows a solution to a somewhat similar problem. You might try checking the whole thread and find possible analogies with your current Ubuntu. Posting whatever partial conclusions also helps.

5. This post and this in old threads for archlinux show a solution to another somewhat similar problem, blacklisting some driver. A similar solution for archlinux is shown here for a soft blocking. So you might try

    echo "blacklist asus_wmi" | sudo tee /etc/modprobe.d/asus_wmi.conf
   

   (used e.g. here, one of the threads where chilli555 took part) and further like here for full blacklisting dependencies. I am not certain asus_wmi is the right module to blacklist. Reboot and run

    sudo rfkill unblock all
   

I guess you might try finding the proper config file where to remove the driver, unblock, and then reload the driver. This seems to do that, but at the command line and for a soft blocking, not the same as your case.

I will wait until you post feedback.

Related

1. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1875921 ?
2. I have to issue "rfkill unblock wifi" at every boot
3. https://classicforum.manjaro.org/index.php?topic=11918.0
4. https://manpages.ubuntu.com/manpages/focal/man8/systemd-rfkill.service.8.html
5. Why Wifi is not working in this Asus laptop of Ubuntu 16.04?
6. WiFi not showing on Ubuntu 16.04 - Asus ROG GL502VMK
7. https://forums.linuxmint.com/viewtopic.php?t=275294
8. How to blacklist kernel modules?
9. How to unblock something listed in rfkill?