Hi,
it's fully normal for a TV set.
In a video Frame, a RGB HSync and the picture start near 0ms but in Composite/Svideo Hsync and the picture start a bit later !
This is why you've got this "problem".
We have it in France since 1980 !
The solutions :
* HACK the "service mode" to "recenter" the TV
-> you'll loose the centering in all other mode !!!
* use the VGA input for RGB
-> if the monitor can handle it... (15Khz...)
* use a broadcast TBC with RGB in/out, with a caption/H.Phase knob !
-> Extra RARE these day and overpriced
:-o Payed mine in 1993 20000 Francs -> 3000 euros ($5000 ?)