Diplomacy aside, we have to keep World war one technology and prevailing naval strategy in mind when thinking about this. Historically, we are still talking about heavy cruisers as opposed to battleships, with much more limited speeds and maneuverability, not to mention firepower. This is why fleet bounce, instead of destroying one another, I think, because that would have been, and was, a rare occurrence with the available munitions calibers.
Now as too an explanation as to why the convoy is not broken, think lines of battle. Two fleets, sailing in single column parallel to one another (no Trafalgars or Lepantos here!) . The convoying fleet, carrying soldiers, is still able to continue moving in it's desired direction, generally at least, right? So it still gets to it's destination.