Greek special character not working Kubuntu 20.04 LTS

[Kostas K]

After a clean Installation of Kubuntu 20.04 LTS (previous version 19.04 with limited support)
I am facing the problem described below In all Kubuntu applications (where I have to type In Greek language) like Kate, LibreOffice etc.
Only exceptions are the web browsers like Mozilla Firefox and Google Chrome. There everything works fine.
Environment languages are First the US English and second the Greek Simple.
The problem Is that I cannot type the most important Greek special character (accent) : tonos (')
e.g. I cannot type the word καλός but instead I come up with the word καλ'ος.
We type the special character need to be shown above the letters by pressing first the :; key next to L and then the specific letter we want to have the special character combined.
The result Is that I cannot practically use edit or create a descent document or note etc. In Greek language.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xserver-xorg-input-evdev 1:2.10.6-1
ProcVersionSignature: Ubuntu 5.4.0-47.51-generic 5.4.55
Uname: Linux 5.4.0-47-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.8
Architecture: amd64
BootLog: Error: [Errno 13] Άρνηση πρόσβασης: '/var/log/boot.log'
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Wed Sep 16 00:31:34 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
InstallationDate: Installed on 2020-06-28 (79 days ago)
InstallationMedia: Kubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
MachineType: LENOVO 2324FV6
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-47-generic root=UUID=b6cedc53-4935-46ac-adb1-641eac0db7d6 ro quiet splash vt.handoff=7
SourcePackage: xserver-xorg-input-evdev
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/19/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: G2ETB3WW (2.73 )
dmi.board.asset.tag: Not Available
dmi.board.name: 2324FV6
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: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrG2ETB3WW(2.73):bd06/19/2018:svnLENOVO:pn2324FV6:pvrThinkPadX230:rvnLENOVO:rn2324FV6:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.family: ThinkPad X230
dmi.product.name: 2324FV6
dmi.product.sku: LENOVO_MT_2324
dmi.product.version: ThinkPad X230
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.101-2
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.8-0ubuntu1~20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2.4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1