Flaky mouse 13.2 KDE radeon

My desktop has been running 13.2/KDE (radeon driver) (wired USB mouse) for about 2 weeks now, generally excellent results
My laptop has been running 13.2/KDE (intel graphics), (Bluetooth mouse) for 1 week plus, generally excellent results.

Desktop was an online (zypper dup)upgrade, laptop was DVD followed up online YAST update.

On my desktop, navigating GUIs, and particularly detailed actions such has highlighting a selection of text in a Konsole session, seems flaky.
Also problematic, in certain situations, is selecting items from a menu or selecting a minimized icon on the Task Manager tray.
I had particular issues editing in LibreOffice, where, for example, trying to place the cursor at a particular character location would select an entire word or an entire paragraph.

In all case, is seems as if mouse click ‘de-bounce’ is not functioning, that a single click is resulting in a two (or more) clicks.
So, for example, clicking a minimized icon on Task Manager tray opens and then immediately minimizes the window.

I have tried turning desktop effects off; interestingly that made things a bit worse.
I have experimented with various settings in System Settings-Input devices-Mouse-Advanced-Double Click interval, which is currently set to 100ms
I would like the mouse to pass on a ‘double click’ sometimes, 100ms has worked for me in the past.

While I look for an alternate wired mouse to try, any other thoughts ?
While hardware failure is always possible, I am more suspicious of a software upgrade contributor.
Is it still true that the low level mouse interface is provided by the video drivers (radeon in this case)?

So far, I do not see this on the laptop, but very different mouse and a different video driver.

So with a little more digging, I believe that the mouse is handled by the xf86-input-mouse package and its driver mouse_drv.so.

I also see more than a few queries like mine that ultimately end in a real hardware issue.

So as a quick test, in System Settings-Hardware-Input-mouse, I switched the mouse to left handed mode.

With a few minutes of use, I conclude that it is likely a problem with my physical left mouse button, things work well with the right click in left handed mode, now clicking left button is flaky for right-handed right-click actions.

Ah well, good-bye old friend :’(