Trying to find out which carrier locked my iphone SE
I bought a new GSM iPhone SE generation 3 which was advertised as unlocked. Used the phone on my existing Cricket account with no problem. However, recently went overseas and discovered that the SIM was locked, so I was not able to replace the SIM with a local carrier SIM. Checked settings>general>about>carrier lock and it shows the SIM is locked but doesn't indicate which carrier locked it. Contacted Cricket customer service and they said they had not locked the phone. Went to ATT's website to unlock phone but they said it was not locked by ATT. Any ideas as to how I can determine which carrier locked the SIM, so I can contact them to unlock it?
iPhone SE, iOS 15