I am happy to report that this bug has been fixed in SU 2 beta (1.4.7.0), although I don’t find it explicitly mentioned in the release notes.
The solution to the riddle is … drum roll … it has to be a summer day (live time).
So let’s wait another 3 months. 
Anyway, I appreciate the fix and other mentioned fixes done to the WP objectives, even if it’s “only” a beta for now.