Why would azure be restarting website when I do a deployment slot

Understanding Azure Deployment Slots deployment slot swap with preview The idea of the swap with preview is that during the first step the configuration settings from the production slot are applied to the staging deployment slot setting in azure If you use the new 'swap with preview' option, it will still restart the app domain, but it will pause before it actually applies the swap

deployment slot A big advantage of swapping deployment slots is that I am able to swap my pre-warmed staging code into the production slot and prevent users