I already went through the unlock steps with AT&T and now I am having a problem with setting up my APN settings for T-Mobile. When I reset the APN settings to default, which now show T-Mobile, the ability to change the ipv4 settings are greyed out. The same thing occurs when I try and add a new APN, no other option other than a greyed out ipv4. I've reset the cache, did a factory reset on my phone yet the same problem exists. I haven't been able to find any solutions to this problem, does anyone know how to fix this? Thanks.