I believe that until recently the great majority of people in the UK pronounced
Maurice the same as "
Morris", while Americans tended to say "maw-REESE", closer to the original French. There is a similar contrast with
Bernard; in the UK that name is normally "BURR-nerd", but in the USA it is normally "burr-NARD".
It is quite possible, though, that with the distribution of American media around the world, that some people in England are now using the American pronunciations of these names.