Samsung and Roku Xfinity Beta 403-102

Need ComcastElla help! We have two homes under one account. The first home has 2 Rokus that work great. The second home has an owner modem. I can’t get the Beta app to work on the Samsung TV or using a Roku. Same message 403-102. I took the Roku that didn’t work to the first home and it works fine. I checked to make sure the correct modem information shows on the account in devices.
I don’t want to continue spending a day on the phone reloading and resetting devices. Any help would be appreciated ComcastElla