Thanks for using our forums. Sorry to hear you are having issues with using your Slingbox with your new router. When you get a new router, you would want to reset the Slingbox and set it back up using the site setup.slingbox.com. You may also need to port forward the router, however, that would be after the Slingbox is set up. Below please find articles for further help.
The Sling Moderation Team