A project that utilises the edbee-lib downstream has found that changing only the white space mode with (void) TextEditorConfig::setShowWhitespaceMode(int) OR void TextEditorConfig::setShowWhitespaceMode(QString) does not in itself flag that a change has taken place that needs a redraw of the editor widget.

As a coder for that project (Mudlet) I have put together a PR that will correct this which I will put up shortly (once I have configured my fork of this project 😁).

HTH!