This is what worked for me.
private const int SCREEN_WIDTH = 128;
private const int SCREEN_HEIGHT = 128;
st7735.SetDataFormat(DataFormat.Rgb565);
st7735.SetDataAccessControl(false, true, true, true); //Rotate the screen.
st7735.SetDrawWindow(2, 3, SCREEN_WIDTH - 1, SCREEN_HEIGHT - 1);
st7735.Enable();
I don’t seem to lose any pixels, I have the full 128 both x and y.
I didn’t make any changes to the driver software. Setting the draw window with x = 2, y = 3 seemed to solve the issue and still use the default 7735 driver software.