Phone not Working S. Korea

[J_Sandlin]

So I bought this phone from my buddy who was using it just fine with a different provider in south Korea. So when I got he said you will have to change the APN. Cool nothing google can't show me how to do. So i go in delete all the APN's and create the new one based off the LG U+ website because that is the provider that I have. Well it didn't work. So I thought maybe factory reset. Still didn't work. Then I saw something. For just a mere second after rebooting my phone every time it registered my service provider and It appeared to have service. But it is only for just a quick second. I did a check online to see if my phone would work with my provider. I found out that it will but only 4g and Band 1-2100MHz, Band 7-2600MHz. Whatever this means. So now i am in a predicament because god help these poor Koreans who didn't know anything. And yes they speak perfect English. So the internet says that the phone should work. The LG U+ says it won't only because it has Chinese on the back. The sub model is the one A2001. If anyone can help me out or maybe shed some light on the situation I would love you forever. Thanks in advance.

 

[Rukbat]

I found out that it will but only 4g and Band 1-2100MHz, Band 7-2600MHz.

Are those the bands the phone will work on, the bands the provider uses, or both? (It has to be both for the phone to work.)