Plugging in CDJ 2000's changes the Deck start and stop times without me knowing, why?

Hi, I tried to play my first gig tonight with a CDJ2000 nexus and a 2000 with a DJM900 mixer. I was able to set up both CDJ easily with two USB cables but after linking both CDJ’s I found in my preferences that start and stop delays had been increased from my previously set 0 to 5 seconds. That really threw off my mixing and It took me valuable time to figure out what was wrong. When CDJ 2000’s are connected why does my pre set Deck start and stop time get changed to 5?