Right mouse click does not work (Ubuntu 18.04.5.LTS)

[r2020r]

I read Secure boot may lead to UNCLAIMED devices "lshw" output, so I providing following data.

No EFI folder

afterwin-2020@afterwin2020:/boot$ ls
config-5.3.0-1045-gke        memtest86+.elf
config-5.4.0-42-generic      memtest86+_multiboot.bin
config-5.4.0-80-generic      System.map-5.3.0-1045-gke
grub                         System.map-5.4.0-42-generic
initrd.img-5.3.0-1045-gke    System.map-5.4.0-80-generic
initrd.img-5.4.0-42-generic  vmlinuz-5.3.0-1045-gke
initrd.img-5.4.0-80-generic  vmlinuz-5.4.0-42-generic
memtest86+.bin               vmlinuz-5.4.0-80-generic

Secure boot command output

afterwin-2020@afterwin2020:~$ sudo mokutil --sb-state​
EFI variables are not supported on this system

afterwin-2020@afterwin2020:~$ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0    7:0    0 243.9M  1 loop /snap/gnome-3-38-2004/39
loop1    7:1    0   2.2M  1 loop /snap/gnome-system-monitor/148
loop2    7:2    0   2.5M  1 loop /snap/gnome-calculator/884
loop3    7:3    0   956K  1 loop /snap/gnome-logs/100
loop4    7:4    0 255.6M  1 loop /snap/gnome-3-34-1804/36
loop5    7:5    0  65.1M  1 loop /snap/gtk-common-themes/1515
loop6    7:6    0   2.5M  1 loop /snap/gnome-system-monitor/163
loop7    7:7    0   219M  1 loop /snap/gnome-3-34-1804/72
loop8    7:8    0  62.1M  1 loop /snap/gtk-common-themes/1506
loop9    7:9    0  61.8M  1 loop /snap/core20/1081
loop10   7:10   0  32.3M  1 loop /snap/snapd/12704
loop11   7:11   0   704K  1 loop /snap/gnome-characters/726
loop12   7:12   0   548K  1 loop /snap/gnome-logs/106
loop13   7:13   0  55.5M  1 loop /snap/core18/2074
loop14   7:14   0 101.5M  1 loop /snap/p7zip-desktop/220
loop15   7:15   0   276K  1 loop /snap/gnome-characters/550
loop16   7:16   0  29.9M  1 loop /snap/snapd/8542
loop17   7:17   0  99.4M  1 loop /snap/core/11420
loop18   7:18   0   140K  1 loop /snap/gtk2-common-themes/13
loop19   7:19   0  55.3M  1 loop /snap/core18/1885
loop20   7:20   0   2.4M  1 loop /snap/gnome-calculator/748
loop21   7:21   0 323.5M  1 loop /snap/kde-frameworks-5-qt-5-15-core20/14
sda      8:0    0   1.8T  0 disk 
└─sda1   8:1    0   1.8T  0 part /media/afterwin-2020/hdd2
sdb      8:16   0 465.8G  0 disk 
└─sdb1   8:17   0 465.8G  0 part /

[mIk3_08]

I removed Gnome

I don't think you have successfully remove the GNOME desktop. I still see it in your desktop information result.
Maybe you have messed up the mix of your desktop with the kde and gnome that causes the system to hang very bad.
I haven't seen any plasma desktop as what you've showed us in the results here in thread.

I installed KDE-plasma and removed Gnome for the sake of testing. KDE-plasma was hanging very badly.

This KDE-plasma is highly configurable it is very nice and pretty. If we need an actual light solution,
and I'm sure it will run smoothly even in the old hardware, you should go for an Xfce, or more likely, LXDE.
These are not that so good looking but its more lightweight than KDE-Plasma

To try out the old kernel, should I go back to PhysicalDisk1 or can select the old-kernel in PhysicalDisk2?
I hope my question is clear..

Don't try to attempt to use the old kernel. If I where you;
use the command

sudo apt update

and

sudo apt upgrade

[ActionParsnip]

If you make a fresh user and log in as that, is it OK there?

[r2020r]

I don't think you have successfully remove the GNOME desktop. I still see it in your desktop information result.

These screenshots are taken after restoring the backup that had 18.0.5 + Gnome. That is why these screen shots still show Gnome.
Before restoring, i did KDE experiment. I have the image of 18.0.5 + Gnome. Before any experiment I restore the image and try.

If I where you;
use the command

sudo apt update

and

sudo apt upgrade

I will try and let you know.

Thanks

[r2020r]

If you make a fresh user and log in as that, is it OK there?

I will try and let you know.

Thanks