Start a new project
add two labels
set one label to SS_CENTER under Windows Styles
Now select both controls (One with Center the other has left)
Uncheck the visible property.
Depending on what control had focus (black handles) the SS_LEFT or SS_CENTER will be set on both controls when changing the Visible style
This is just one example. Any style change causes all styles to match the control with focus.
That is by design. When a group of common controls are selected and you change any of the "(WindowStyles)" property items then the whole group of items that compose the WindowStyles are applied to the other selected controls.
That is, the individual stlyes in the WindowStyles property group are not treated individually - they are treated as one group.