Samsung A70 ineligible for Bring your own device?

Visited an xfinity store today to start up new service for the Samsung Galaxy A70 I bought 2nd hand and was turned away after being told the device is not compatible with their bring your own device program. I was told things like "the technology doesn't work for it" "it isn't a galaxy" "it just doesn't work I dont know why" "it only works with the s9 and up"" it only works with the s8 and up" "it doesnt work with the s7" (how convenient that's what I have!)

Here's the real answer- it's a dishonest ploy to get you to just buy their phone instead.

How could the technology not work when this phone was exclusive to xfinity?
How could this phone not work when it is currently asking me to install an xfinity sim card?
How could it not work when the phone is unlocked?
How could it not work when I enter the IMEI number on the xfinity website it says it is compatible?

Is xfinity going to send me this card knowing full well it won't work?

I'm attempting to use the card I ordered on their website since it let me and we'll see what happens.

If someone has the actual real answer to why they wouldn't chose to let it work for me I'd like to know. The "technology" is the most bs reason I've ever heard when I can literally buy a new one from them and it works.