Hello,
If you select from KDE desktop SUSE Help Center, open application manuals, open KDE Introduction and openKDE user's manual you see/experience the following:
On the 1st page there is a next button at the top(top Right) as well as at the bottum/end (bottum Right) of the page.
If you approach with your mouse pointer the word "Next" from below than, for the top of the page next button, the word next is selected if you are roughly half a letter height below the word next and the word next is deselected if the mouse pointer is moved to roughly a half letter height above the word next.
For the bottum of the page next button the behavior is different. The word next is selected, coming from below with the mouse pointer, as the pointer is already above the word next and moving upwards the word next is directly deselected. This give sometimes the impression that you cannot use this next button.
The next buttons, top as well as bottum, on the following pages function correctly, similar as the top of the page next button described earlier.

This behavior already existed in Suse 9.3
This behavior exists on my laptop as well as on my desktop.