Vertically shifted image issue

[yoZencolere]

Hello,

I have a vertical image shift problem with my gdemu and some gdi's like tokyo xtrem racer. The image is shifted downwards, it only occupies half the screen and it is in 50hz.
It's a European console originally but I flashed the bios to make it run natively in ntsc.
I have tried every possible option in sd card maker like enabling vga, changing the region, changing the gdi region options. I've tried several versions of the game and whether it's the US or European version, the problem persists.
If anyone has an idea as this problem is driving me crazy.
I'll be happy to help.