Not registering Modem caused ISP to not accept modem

[Steve40th]

Not sure if I am understanding this or how to search.
I had internet issues back in Feb. Long story short ASUS router died.
Then last week, more issues, and I replaced my SB8200 ( I thought it was the 6183) with a S33. My girlfriend had to as I was away.. Then it died a few days later. Rebooted, worked for a couple more, then finally it died.
Xfinity came out and just left. They check everything from hub to back of modem. All is fine. Hooked TV to modem directly, to bypass ASUS, and still nothing.
Make a long story short, xfinity, even though they registered the S33 had my old modem still in the system, and kept blocking new modem. And due to it not being registered, they were cutting it off.
Due to me not being there, they put my 8200 back in and it immediately worked.
So, how is it possible for a modem to not work at Xfinity even though they activated it several times?
Tried to register today, no phone support and live chat was down.

 

[sfx2000]

If you have replaced your modem, then you need to sort it with the ISP

 

[Steve40th]

I did.
Xfinity tech showed up. They tried everything to activate it. They had two techs on speaker phone working with him to get it done. It was connected, they saw it, but no data. They ran ethernet directly to the tv, laptop and their was nothing. The ASUS was working fine, no red light on, and the laptop and TV saw it, but when logged in, no data.
The account had my old modem still in there. I think that there tells me their end is the problem. When activated, the new modem shows up, but is offline, even though it shows the modem. But modem was offline. It worked a bit, then quit for a couple days..
So, Cable was looked at and fixed, according to xfinity. What they fixed is unknown.
But, once they put my old modem back in and activated it again. Everything worked fine.

 

[Tech9]

There is nothing you can fix on your end.

 

[Steve40th]

An xfinity person reached out and believe Xfinity failed the provisioning of the modem. Not sure what that means

 

[Steve40th]

Xfinity person I spoke to is getting the entire run from hub replaced. He put in a emergent ticket.
So, at least the outside will be fixed.
Then, he said, when I get back, call him when ready to activate modem, and he will provision it properly and delete the other modem. He feels that is where they kept failing today and the other days.