I am running two laptops, both Thinkpads and looking identical as far as keyboard and case are concerned. They are both running TW on KDE desktop but only one has this keyboard problem.
I am revisiting this as it is driving me mad. One laptop works as it should with GB setting in Yast>Language as GB and a GB keyboard. My other laptop is firmly stuck in US mode although all the settings for GB are correct.
I recall somebody explaining this problem was caused by some other KDE app but cannot find the thread. I want to find it or rather what app causes the problem and if OK remove it so my keyboard works as it should.
Do you have IBus installed? I did, and had exactly the same issues. If you do you need to set the keyboard in IBus Preferences (Menu: System =>> Preferences =>> IBus Preferences). I have posted this before and one of the admins suggested simply uninstalling IBus.
I have not been able to find any obvious means to edit the ibus-config settings and either my system is different or what I seek has been hidden.
Reading the existing ibus-config file I find the instructions there quite confusing.
As a layman I find this one of the worst examples of finding yet another way to do something which isn’t needed by most, with no clarity of precedence of commands and witnessed conflicts between otherwise good system settings.
Rant over, I shall just disable ibus as I have not found how to edit settings.
My thanks again to JulinaB