Pixel 4 XL | Xfinity Mobile will not work/activate

My new, unlocked, Pixel 4XL, will not work with the Xfinity Mobile network. If I make a call, I get routed to customer service. Customer service says my IMEI is not compatible but my phone will work on other networks without issue (Verizon, TMobile, and Cricket).

There's a thread listed: https://forums.xfinity.com/t5/Xfinity-Mobile/XM-cannot-BYOD-brand-new-unlocked-Pixel-3a-phones/td-p/3291366

that sounds like my problem and wondering if @ComcastChrisL has a potential solution versus me spending another 3 hours with customer service.

Thanks!