MAX BR1 Pro 5G will not connect to T-Mobile or Mint

I have tried the 50G prepaid plan from T-Mobile. It will not connect—just says “connecting”. I’ve set the APN to fast.t-mobiles.com.

Same with the Mint pre-paid plan.

When I called their tech support, both said the IMEI was not compatible, but I have seen others on here with success.

Please help! I’m out of things to try.