troubles rotating a boxmask in sync with a box.

hello there !
i try to synchronize a boxmask in a material to a collision box . the position and size of the boxes respond well. but when it comes to rotate the box around it s center it s starts doing strange things ( i think it s a math probleme here )
i v made a basic UI with slider to control the box position and rotation , but when i rotate it, it rotates more than the box , ( and i tried to divide the rotator, but it work only on -90 to 90 and has a strange behavior)
here in video :

here are the BP :
when i change a value in a slider, it updates the rotator parameter (the angle is linked to a slider at 0.5 default value)

and the material nodes :

i think i missed something about the vector math behind this. if you have any solution i ll be glad !
thanks in advance.