createDmSession.403-102 On Roku after replacing cable modem

I am having an issue that others have previously had, based on prior posts.  I recently switched to a personal modem and shortly afterward our Xfinity Stream app on Roku and iOS stopped recognizing our home network.  @ComcastChe  appears to have helped people with this before.  Can @ComcastChe  please assist me as well?  I have spent 5 hours on the phone and chat with "Advanced Review" but they are useless, unfortunately.   Thank you.