There is always more to say, but I addressed the question of whether John's baggage was ever actually lost at all in response to an earlier question here a few months back:

Why was King John even attempting to cross the Wash when he was going to Lincoln? The map suggests going across the Wash wasn't a direct route so why attempt it when it was known to be potentially dangerous?

You might like to review that answer while you wait for other responses to your query.