Unable to remove control points

Hi guys!
I wonder how I can delete unwanted control points in Viveza 2. Referring to the support page, it says “select the control point and just hit backspace on mac”. Unfortunately this procedure does not work anyway - it has no effect at all. Curious - deleting control points this way works with all other plugins within Nik Collection 2.

Any ideas how to make it work or work arounds?

Delete entire Nik Collection from MacBook and re-install it also does not solve my problem.
Many thanks in advance.