Thanks for using the forums! That's a great question! Anytime you change service providers, or the router or modem is changed, the Slingbox needs to be reset to factory settings. After that, you will need to go to setup.slingbox.com and go through the online setup to reconfigure.
Below is a link to an article that explains how to reset your Slingbox to factory settings:
Hope I was able to help!
The Sling Moderation Team