Question settings not saved

I want a question with multiple choices and wante this question to be correct (1 point) if ALL answers are right and 0 point if anything is wrong.

I’ve try to check “Treat this question as a whole” and set 1 point if question is correct and 0 if wrong.

When I save the question and go back on this question: settings were not saved.

I check the database, and the value ‘calculate_whole’ in watupro_question stay at 0.
I wrote 1 and checked into backoffice, the setting is displayed. I’ve change reward_only_correct to 1 and discard_even_negative to 0: no change in backoffice.

Important: when I try to change these settings by the backoffice, no matters of value, the ‘calculate_whole’, points if correct, points if wrong are set to 0.

PS: I’m using WordPress 4.9.1 and WATU Pro version.

Thanks!