I got mine in this week too. My RIS went from 41.5 in the first round to 31 in the second round, which is a little confusing. Maybe they were judging to a higher standard in the second round? It is a little under-attenuated because the yeast gave out after 14.5% abv!
Different judges, different bottle (?), different tasting order, etc, all of these things can affect how the beer is perceived. You got some good scores there, I'd be happy.
Other potential factors:
More experienced judges - less likely to be wowed by extreme beer, more persnickety about judging to style.
Beer warmed up or served too warm/cold - too warm might make a big beer seem too alcoholic, too cold keeps it from "opening up" properly.
Judging hall warmer/colder - my experience is that big, malt-focused beers seem more cloying and less satisfying if the hall is too hot, but more appealing if the hall is too cold.
Going from 41 (potential BoS winner) to 31 (good, but likely not a winner) is a big drop. Take a careful look at your scoresheets from the first and second rounds and try to figure out what changed.
If you're still confused and the judges had the guts to put their email addresses on their scoresheets, there's no harm in emailing the second round judges and politely asking why they assigned the scores they did. Chances are, however, they won't remember your beer in particular, so you might need to give them brief quotes from your scoresheet.