Apple, copying others and calling it magic since 1976!
Sounds like TracFone is tweaking their system. Hopefully BYOP is back up and works better.
As far as unlocked Chinese phones, I know it's confusing, but WCDMA is not the same thing as regular...
I believe the iPhone 5S/5C supports those as well, Note 3 as mentioned above, Nexus 5, HTC One, Moto X, Lumia 1020, Nexus 7 LTE, BB Q10, Xperia ZL/Z1/Z Ultra, LG G2, and probably others to come. So...
for as far as my knowledge is concerned team skidrow have made a samsung unlock code generator for this
check the site samsungunlockcode.tk
im still using it and i still dont have any problem. however the features is a little bit outdated
i had similar problems but i had it fixed.. i will post the fix later