drawdefaults
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The rectangle to the left of this text was created using “Rectangle” tool with drop-down. This rectangle exhibits the bug.
Select the rectangle and change the fill type/color from Color/Black to None. Note that it will remain black.
If you move it, it will redraw. After it redraws, change it back to Color/Black. Note that it will not redraw until you move it.
The rectangle to the side was created using the default “Rectangle” tool that does not have a drop-down menu. This rectangle does NOT exhibit the bug.
Select the rectangle and change the fill type/color from Color/Black to None. Note that it will change as expected
For additional testing, I've attached a toolbar to this drawing that includes the two types of “Rectangle” tools. LO seems to want to put this toolbar right before the “New” and “Open” tools. If it's not already active, enable it using
View → Toolbars → ”RECTANGLE_EXAMPLE”