SDL2 - VSYNC active, but tearing at specific window height - c++

Question

I am using SDL2 in windowed mode on Windows 7 64bit to create a small game.
I get tearing at the same height of the window despite having VSYNC active. The weird thing is that the movement in itself is fluid, but there is this line, about 50px from the bottom, where tearing is noticeable. It always stays there, without moving or anything.
The weird thing is that if I crate a smaller window, I get tearing at exactly the same height from the bottom.
I tried taking screens of it but it doesn't show the tearing.
I have no idea if this is a problem of SDL2, a problem with Windows, a problem with my pc or a problem in my source file. I have tried looking online for a solution but I could not find anything like this problem.
It is a first for me since I have been playing with a lot of SDL games in the past in windowed mode and none had this problem.
Here is a snippet of the source I have been using:
#include <stdio.h>
#include <SDL.h>
#include <SDL_image.h>
const int SCREEN_WIDTH = 400;
const int SCREEN_HEIGHT = 300;
bool init( SDL_Window** window, SDL_Renderer** renderer ) {
SDL_Init(SDL_INIT_VIDEO);
*window = SDL_CreateWindow("Test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
*renderer = SDL_CreateRenderer(*window, 0, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
int flags = IMG_INIT_PNG;
IMG_Init(flags);
return true;
}
void close( SDL_Texture** image, SDL_Window** window ) {
SDL_DestroyTexture( *image );
*image = NULL;
SDL_DestroyWindow( *window );
*window = NULL;
SDL_Quit();
}
int main(int argc, char* argv[]) {
SDL_Window* window = NULL;
SDL_Renderer* renderer = NULL;
SDL_Texture* image = NULL;
const SDL_Rect rect = { 0, 0, SCREEN_WIDTH, 200 };
SDL_Rect rectImage, rectImageOriginal;
int w, h;
SDL_QueryTexture(image, NULL, NULL, &w, &h);
rectImage = { 0, 0, w, h };
rectImageOriginal = rectImage;
init( window, renderer );
image = IMG_LoadTexture( renderer, path );
while (running) {
[... here I move rectImage ...]
SDL_RenderClear(renderer);
SDL_SetRenderDrawColor(renderer, 200, 0, 0, 255);
SDL_RenderFillRect(renderer, NULL);
SDL_RenderCopy(renderer, image, &rectImageOriginal, &rectImage);
SDL_RenderPresent(renderer);
}
close(&image, &window);
}