Moving iPhone X from AT+T to Verzion

Verizon is telling me that I can move my ATT purchased over to them, but I don't think that is the case. ATT seems to be horrible with this chipset on the iPhoneX and when I inquired about a year ago, they said it wasn't possible, but now it is?? I entered my IMEI # on Verizon and it says it is compatible, but then said NON VERZION CDMA LESS as a status. Verizon support tells me I can move with no issue. Is there anywhere I can check without making another purchase and regretting it? In the past I read that 2 different chipsets came with ATT and I have the one with the bad modem, yet ATT will do nothing to fix it, so I have to switch. Thanks everyone