[Q] Unlocked Sprint M8 Still can't use AT&T or T-Mobile topic

I bought a used Sprint M8 Not HK version
And I successfully unlocked the simlock,because I have been to China and I can use the GSM and CDMA network there.
I want to change my carrier as AT&T or T-mobile even if Version Wireless,but it just tell me the SIM Card Is Invalid !

I visited a lot of website and tried any possible solution on the Internet,include but not limite in: Change ROM,Flash Radio,Format /cache /sytem /data,Retry simlock again and again,Set QPST,Set CDMAworkstation,Set DFS ...

Well,
I even want to buy the unlock code from xxxxxx.com,but they warn me do not buy the code if the phone didn't request.
Why the phone didn't request the unlock code?
I truly hope I can unlock this phone,
If you know how to deal with it,Please help me!

I am using Sprint (maybe)original ROM,Software version 3.31.654.2,OS vision Android 4.4.4,Baseband version 1.08.20.0916