What makes me wonder, is that IncrementalSearch still works, but HighlightOccurrences does not.
And the ClearRange code is the same in both cases.
We can do the Refresh as workaround for the moment, but it looks like there must be some deeper issue that should be fixed, before it bites us at another place.
At the moment I would prefer not to change the (wx)scintilla code, if it is not definitely caused by it.
But (as I posted) before, HighlightOccurrences work with wxSTC and IncrementaSearch works with "our" wxScintilla.
So it might still be something in ouzr code, probably in our (wx)scintilla-changes.