Rackets break at 3 or 9 o clock

Hello guys,

I currently have quite a much of racket breakage at 3 or 9 o’clock while stringing at tension >13kg.

I didn’t happen much with my old customised pro’s pro but since i switched to the stringmaster 3700 (with head 2086 engine) it happen quite often…

From what i can see, side supports seem too far from each other but i can’t get them closer.

Do you guy’s have a solution ?
I’m quite desperate actually…