Two step verification: SMS to Canadian number doesn't work

Just wondering if there are any other Xfinity customers with Canadian mobile numbers who have managed to get 2FA or any text messaging with Xfinity to work at all. I have been trying off and on for years, but no text message ever arrives at my Canadian number. I have many other US-based businesses and people who are able to message me, so I don't think the problem is on my end.

I'm looking for a solution, or acknowledgement that Xfinity doesn't support 2FA with non-US numbers (in which case, stop sending me reminders to enable it).