It's a problem with Arabic language - because it goes opposite direction then European languages - from right to left. This is why plus and minus sign jumps from left to right.
I have experienced absolutely the same problem in Israel with Hebrew.
It was possible to play with some parameters in Windows 10 to control this problem, but as I remember in half of the computers it didn't work properly.
The only solid solution I found - I programmed my own labels and markers, where GDL code did force the position of plus and minus sign. I needed literally split sign and number into two text blocks and place each in the right position.