I just activated my Honor 5X with AT&T yesterday, and noticed that MMS messages won't show pictures, only a download link, which never downloads. Also, when not on wi-fi, there is no internet available. I contacted customer service, and they walked me thru setting up an APN with the following:
Name: NXTGENPHONE
APN: NXTGENPHONE
Proxy: Not set
Port: Not set
Username: Not set
Password: Not set
Server: Not set
MMSC:
http://mmsc.mobile.att.net
MMS Proxy: proxy.mobile.att.net
MMS Port: 80
MCC: 310
MNC: 410
Authentication type: Not set
APN type: default, mms, supl, hipri (spaces after commas are intentional)
APN protocol: IPv4
APN roaming protocol: IPv4
APN enable/disable: APN enabled (this locked as enabled)
Bearer: Unspecified
MVNO type: None
MVNO value: Not set (this also locked)
She also registered my EMEI, which was still showing as my Galaxy S4.
Anyone have any ideas on how to proceed? Any help would be appreciated.