Upgraded and lost connection

Hello. 

We had wifi with a good connection before we upgraded at the xfinity store and came home to no wifi (makes sense). We could not setup the XB8 as it just keeps flashing orange and green. CS/TS could not solve the issue. A tech is coming out Saturday. 

How is it possible that we had a good connection before we upgraded and now switching from the xb7 to the xb8 we lost our connection.