No wifi detected on lenovo thinkpad t14.s

I've just bought a lenovo ThinkPad-T14s-Gen-2i and installed Ubuntu 20.04.3. Unforunately it doesnt register the wifi.

I've turned off secure boot prior to installing ubuntu.

I hope someone knows how i solve this.

I get the following output from lshw command

 *-network                 
       description: Network controller
       product: Intel Corporation
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:09:00.0
       version: 1a
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list
       configuration: driver=iwlwifi latency=0
       resources: irq:16 memory:bc200000-bc203fff
  *-network
       description: Ethernet interface
       product: Ethernet Connection (13) I219-V
       vendor: Intel Corporation
       physical id: 1f.6
       bus info: pci@0000:00:1f.6
       logical name: enp0s31f6
       version: 20
       serial: 38:f3:ab:c3:bb:b5
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=5.10.0-1051-oem firmware=0.8-3 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:147 memory:bce00000-bce1ffff
  *-network
       description: Ethernet interface
       physical id: 2
       bus info: usb@3:7
       logical name: usb0
       serial: 02:60:22:a9:ab:48
       capabilities: ethernet physical
       configuration: broadcast=yes driver=rndis_host driverversion=5.10.0-1051-oem firmware=RNDIS device ip=192.168.106.32 link=yes multicast=yes

I get the following output from lspci:

00:00.0 Host bridge: Intel Corporation Device 9a14 (rev 01)
00:02.0 VGA compatible controller: Intel Corporation Device 9a49 (rev 01)
00:04.0 Signal processing controller: Intel Corporation Device 9a03 (rev 01)
00:06.0 PCI bridge: Intel Corporation Device 9a09 (rev 01)
00:07.0 PCI bridge: Intel Corporation Device 9a25 (rev 01)
00:07.2 PCI bridge: Intel Corporation Device 9a27 (rev 01)
00:08.0 System peripheral: Intel Corporation Device 9a11 (rev 01)
00:0a.0 Signal processing controller: Intel Corporation Device 9a0d (rev 01)
00:0d.0 USB controller: Intel Corporation Device 9a13 (rev 01)
00:0d.2 USB controller: Intel Corporation Device 9a1b (rev 01)
00:0d.3 USB controller: Intel Corporation Device 9a1d (rev 01)
00:14.0 USB controller: Intel Corporation Device a0ed (rev 20)
00:14.2 RAM memory: Intel Corporation Device a0ef (rev 20)
00:15.0 Serial bus controller [0c80]: Intel Corporation Device a0e8 (rev 20)
00:15.1 Serial bus controller [0c80]: Intel Corporation Device a0e9 (rev 20)
00:16.0 Communication controller: Intel Corporation Device a0e0 (rev 20)
00:1c.0 PCI bridge: Intel Corporation Device a0b8 (rev 20)
00:1c.4 PCI bridge: Intel Corporation Device a0bc (rev 20)
00:1f.0 ISA bridge: Intel Corporation Device a082 (rev 20)
00:1f.3 Audio device: Intel Corporation Device a0c8 (rev 20)
00:1f.4 SMBus: Intel Corporation Device a0a3 (rev 20)
00:1f.5 Serial bus controller [0c80]: Intel Corporation Device a0a4 (rev 20)
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (13) I219-V (rev 20)
04:00.0 Non-Volatile memory controller: Toshiba Corporation Device 011a
09:00.0 Network controller: Intel Corporation Device 2725 (rev 1a)

Based on the computer's specs pdf given here, you have one of the modern Wifi cards such as

• Intel Wi-Fi® 6 AX200, 802.11ax 2x2 Wi-Fi + Bluetooth 5.2
• Intel Wi-Fi 6 AX201, 802.11ax 2x2 Wi-Fi + Bluetooth 5.2
• Intel Wi-Fi 6E AX210, 802.11ax 2x2 Wi-Fi + Bluetooth 5.2

and the issue might be about your kernel version. For example if you have (Intel Wi-Fi® 6E AX210) it requires at least kernel version 5.10 and can verify this at here. Please check your kernel version with uname -a command.

As stated in one of the answers in this link, "The Linux 5.10 kernel (or later) will ship as part of Ubuntu 21.04 in April. This version will also get backported to Ubuntu 20.04 LTS at a later date. It's possible to manually install a mainline kernel in Ubuntu however if it breaks you get the pieces." You can install kernel 5.11 to make the wifi adapter work, but as suggested in the same answer be warned to review the implications of installing a kernel version manually here.

Installing Kernel 5.11

• First install Mainline as a graphical kernel installing tool. (See details here)
• run sudo add-apt-repository ppa:cappelikan/ppa
• sudo apt update
• sudo apt install mainline
• Open Mainline Kernel Installer and install 5.11.0
• After installation, reboot.
• sudo update-grub and sudo reboot
• As described here, the output of sudo dmesg | grep iwl will show us some errors with the information about which firmware we need to install.
• For example you might need iwlwifi-ty-a0-gf-a0-39 to iwlwifi-ty-a0-gf-a0-59.

Installing Firmware

• At the output of dmesg command it is suggested to check https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/
• Go this website and download the newest firmware (eg. as of today it was linux-firmware-20211027.tar.gz (sig))
• It takes some time to download, be patient
• Uncompress the file with tar -zxvf linux-firmware-20211027.tar.gz
• cd linux-firmware-20211027/
• Copy the firmwares to /lib/firmware/ with command sudo cp -ax * /lib/firmware
• Now reboot and the wifi should work!