Talking with T-mobile tier 3 support are lost with this question.
Why do a old Voicestream sim work in a 3650 and the New T-Mobile doesn't

T-Mobile Sim Locks the 3650 phone up at the Clock and Battery Screen. (home). No keys or activity on the phone. Totally locked. Have to pull battery. Power shut down doesn't work either.

Tried several Dozen T-Mobile sims and the Same thing happens.

Now the Voicestream Old (Green & Blue ) on back of sim work 100%

Is there an Issue with Newer T-Mobile sims that we are not aware of.

Any Help will be appreciated.