[ThinkPad E14 Gen2] Closing the lid does not trigger system suspend - fn keys not working

According to the system settings (see the attached screenshot), the laptop should go to sleep (suspend to RAM) when I close the lid. However, closing the lid has no visible effect.

'systemctl suspend' works OK, choosing 'Leave' -> 'Sleep' in the menu works too.

After suspend and resume, closing the lid starts working as expected and is triggering suspend to RAM. So this might be related to BIOS, ACPI or something similar.

I am filing this bug against 'linux' package because, perhaps, a quirk could be added in the kernel as a workaround. IIRC, the kernel had a number of quirks to work around BIOS/ACPI problems.

A similar issue exists with Fn keys on this machine: they do not work after a boot but start working after I have suspended and resumed the system (checked with Fn+F5/F6 - brightness down/up). Others encountered that too (see [1], [2] below). I suspect it is caused by the same bug in BIOS or ACPI.

ThinkPad E14 Gen2 with AMD Ryzen 5 4500U
Machine type model: 20T60030RT

UEFI BIOS ver: R1AET33W (1.09), the latest version at the moment
Embedded controller FW ver. R1AHT33W (1.09)

SecureBoot: off

OS: Ubuntu 20.10 amd64

Kernel 5.8.0-40-generic.
I have also tried the builds of the newer mainline kernels:
* 5.9.0-050900-generic from https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.9/amd64/
* 5.10.0-051000-generic from https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.10/amd64/
The issues with lid closing and Fn keys show up there too.
----

[1] https://askubuntu.com/questions/1289640/fn-key-doesnt-work-in-ubuntu-20-04-on-lenovo-thinkpad-e14
[2] https://forums.lenovo.com/t5/Other-Linux-Discussions/Linux-Fn-keys-not-working-Thinkpad-E14-AMD-Gen-2/m-p/5027791

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: linux-image-5.8.0-40-generic 5.8.0-40.45
ProcVersionSignature: Ubuntu 5.8.0-40.45-generic 5.8.18
Uname: Linux 5.8.0-40-generic x86_64
ApportVersion: 2.20.11-0ubuntu50.3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: alina 1059 F.... pulseaudio
                      alina 1062 F.... pipewire-media-
 /dev/snd/controlC0: alina 1062 F.... pipewire-media-
 /dev/snd/seq: alina 1058 F.... pipewire
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Sun Jan 24 17:09:34 2021
InstallationDate: Installed on 2021-01-18 (6 days ago)
InstallationMedia: Kubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
MachineType: LENOVO 20T60030RT
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.8.0-40-generic root=UUID=1b0f22fc-c314-411c-87c4-ef7e71326576 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-5.8.0-40-generic N/A
 linux-backports-modules-5.8.0-40-generic N/A
 linux-firmware 1.190.3
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/26/2020
dmi.bios.release: 1.9
dmi.bios.vendor: LENOVO
dmi.bios.version: R1AET33W (1.09 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20T60030RT
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.9
dmi.modalias: dmi:bvnLENOVO:bvrR1AET33W(1.09):bd10/26/2020:br1.9:efr1.9:svnLENOVO:pn20T60030RT:pvrThinkPadE14Gen2:rvnLENOVO:rn20T60030RT:rvrNotDefined:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad E14 Gen 2
dmi.product.name: 20T60030RT
dmi.product.sku: LENOVO_MT_20T6_BU_Think_FM_ThinkPad E14 Gen 2
dmi.product.version: ThinkPad E14 Gen 2
dmi.sys.vendor: LENOVO