Projucer proportional width strange behavior OS X 11.1

Hi I have a strange behavior in projucer. I don’t understand what I’m doing wrong.
My JUCE version is said up to date.
I ended up doing a small test :
I create a new GUI component with say initial width in class = 600
I add 3 rectangles with x = 0 and width = 600
1st rect : I change width mode to percentage of parent width. It says 40,053% and not 100%
2nd rect : I stay in absolute width = 600
3nd rect : i set width mode to 100% then switch back to absolute width, it says 1498 and not 600

the GUI editor windows shows a 1498 width and not 600
with command T : only the 2nd has the right width (= full window width, 600 I assume, but of course rect doesn’t get resized
It’s a big problem as I have to mix both modes in the real screen I try to do and I’m in trouble to design anything.
Would you know what happens ? Regards. LucB