Hello Ichfxbark,
Welcome to the community!
Firstly, do you know what version of that phone you have? These are some of the band/frequency specifications I have found for that phone:
A: 2G (GSM): 850 / 900 / 1800 / 1900 MHz 3G (WCDMA): 850 / 900 / 2100 MHz 4G (FDD-LTE): B1(2100) / B3(1800) / B7(2600)
~taken from here.
and
B: 2G: GSM 850/900/1800/1900MHz 3G: WCDMA 850/1900/2100MHz 4G: FDD-LTE 800/1800/2100/2600MHz
~taken from here.
Judging by those specifications, both versions have all of the compatible bands/frequencies for 2G. On the other hand, version A only has 1 compatible '3G' band/frequency while version B has both. With regards to LTE, both versions appear to only have one compatible band/frequency, band 7 or 2600MHz. You can verify the compatible bands/frequencies here.
While the phone should work on the networks, coverage depends on corresponding bands/frequencies available at your surrounding cellular towers. Not all bands/frequencies are used at all cellular towers. You can get an idea of your surrounding cellular towers here.
In addition, it should be noted that the different bands/frequencies have varying characteristics. For example, the higher frequencies generally have a greater potential bandwidth than the lower frequencies (see table here). On the other hand, the higher frequencies tend to decay faster. That is, they do not travel as far, nor penetrate as well as the lower frequencies (see graphic here).
It's possible there are different versions of that phone with differing specifications as well.
Out of curiosity, where did you find that APN information? Since the phone is LTE-compatible, it should be using ltemobile.apn. You can verify those settings here.
Have you tried to enable roaming data? Occasionally, phones from elsewhere think they are roaming even though they might be using a local SIM.
Hope this helps 
Cheers
