If you are on the elevator when the round finishes some funky things happen. It won't go down until you step off for a minute and just wait until it refreshes or something I guess? Idk
Well by odd I mean buggy. I don't remember for certain, but I think it's along the same lines as the need for enemy AI to wait a second or two before initializing once the player is on the arena floor. In both cases it prevents something from breaking, but I don't know what specifically.