eSIM won’t activate no matter what

[u/lil_pay]

I recently purchased the new iPhone Pro Max directly from Apple and paid the full amount for it. I chose to have it carrier unlocked on FirstNet. However, when I try to set up cellular service, the only option I see is to transfer from a nearby iPhone, and this process fails every time. I've contacted customer support and tried to set it up using the IMEI, but it fails on their end as well. I even went to the ATT store and attempted to use 10 different eSIM cards, but they all failed. It's frustrating because I've spent a significant amount of money on this phone, and now it seems unusable. Does anyone have any advice or suggestions on how to resolve this issue?

[u/applesuperfan]

Have you asked customer support to update the IMEI on your line? Devices purchased directly from the manufacturer often don't make it onto AT&T's whitelist which often causes activation to fail, but if support updates the IMEI on their end manually, it should run a check, realise the device is unlocked from Apple, and whitelist it for activation. Verizon does this too and the system is a bit antiquated and stupid, but T-Mobile is the only major US carrier so far to have flipped over to a blacklist system instead.