Can't Transfer Galaxy A51 Phone from Verizon to Xfinity Mobile????

After multiple IMEI checks and chats with support, supposedly the Galaxy A51 phone I bought 1 year ago and paid off is not "compatible" with Xfinity network. Yet....  wait for it......  they offer the exact same phone on their website! Was told the technology is different between phones.  To which I replied OK I know that but it is literally the EXACT SAME PHONE, made by the exact same company. It isn't a different model, not a dfferent brand,.... nothing is different. So how can the technology be different????  I think Xfinity mobile either has to update the IMEI list or they are trying to scam people to purchase the exact same phone they already have and are using the "different technology" and "network incompatibility" as an excuse to make the scam work.