Phone replacement is locked to xfinity, but I signed up with bring your own phone, which was unlocked

Hello, I signed up for xfinity internet and received a free mobile line. I brought my own phone, which was an unlocked iPhone 15 Pro Max. Signed up for insurance during the signing up for the free line. Screen got cracked as well as the back. Sent in to their repair store, they replace both glass panels, but the motherboard was broken. Now I need a new phone because its stuck in a loop. I receive the phone, but now its locked to xfinity instead of being like my phone that i brought to xfinity. I need it unlocked becasue I use the xfinity line as a secondary, not my main.