I have looked into what bands the Xperia Z5 Premium E6853 (originally from Canada) and T-Mobile share on 3G and I have found (sources at the bottom) that they share UMTS HSPA+ 1900MHz (Band II) and 2100MHz (Band I) and yet I can only get 2G and LTE to work at all.
Along with this issue is another, I can text and use the internet on LTE but cannot recieve or make calls despite the Z5 Premium sharing the 2,4,5, and 12 LTE bands with T-Mobile. I have subsequently set the phone to LTE/UMTS auto (PRL) so I can make calls, but if I set the phone to LTE I get
Voice Service: In Service
Data Service: Connected
Voice Network Type: LTE
Data Network Type: LTE
Ping Hostname (www.google.com) IPv4: Pass(2)
Ping Hostname (www.google.com) IPv6: Fail(2)
HTTP Client Test: Pass
But if I then try to call voicemail the phone immediately ends the call. Only texting and Data work on LTE so I can only call people using GSM 2g/Edge.
Truth be told I am on MetroPCS but since T-Mobile owns 'Metro' and that they share the same cell towers so I thought it best the question here as the local MetroPCS store employees just say there might be so problems do to cell tower upgrades and are unable to go into anymore detail.
I want an as technical an answer as possible. Is it the phone, the sim or the network that is the issue?
T-Mobile/MetroPCS: T-Mobile network
For 3G, T-Mobile doesn't use Band 1. It uses 1700/2100 as Band 4. 1900 / Band 2 is not rolled out in all markets.
The device may not have VoLTE or be configured to work with T-Mobile's VoLTE. That's why setting it to LTE only doesn't work. The suggested setting is LTE/UMTS auto (PRL) on devices (it's what's selected by default)
Manage your T-Mobile account