Thank you for your replies.
I am aware of the compose key need in a number of European languages (I have the danish Keyboard layout as alternative) but as an example Belgian/French keyboard would probably have more need for compose. I had already been in that area and expanded the compose option to check, even though the section square had no indication of selection had been activated. Better safe than sorry.
The keyboard I am using is the same keyboard used in the 'good' KDE-mini (same PC just quick re-start to change), it is not faulty.
I went back to the Locale area again to triple check, and pausing looking at the keyboard maps I had installed,
dk and
us and then it dawned on me the
us keymap had a comment in variant field about US international. I had a vague memory about variation that I had looked into this a number of years ago. I switched this to no variant
US. I admit that was a good trap. Now it is working proper

I am not sure when or where that change came about, the OS was installed under a bit of pressure and it is first now that I have settled back to trim the corners to my use.
I also walked physically away from the pc for 30 minutes, very hard to do when one of these simple problems are only 30 seconds away, the snag is that 30 seconds starts laughing at you soon.
