I am trying to book a single flight in Y from NBO to LHR via DXB. It is a great fare of U$320 and the fare rules state that a free stop over is permitted. I would like to have a day in DXB but when I plan that the fare jumps up to U$2140. I am I missing something. (would like fly the A380)

(I tried it in the advanced menu and in the stopover menu on emirates.com)

My thanks in advance to anyone who can help me out.