Used S7 edge firmware issue

[googleccd]

I bought A used S7 edge, I have issues with 4G use on my phone, and It wont update past android version 6.

When I used SAMSUNG INFO app I found the following:
Bootloader Version: G935VVRU4API3
PDA Version :G935FXXU1BPL2
CSC Version :G935FXXU1BPL2
Baseband Version :G935VVRU4API3
CSC COUNTRY : HONG KONG
SAMSUNG SERIAL NUMBER : 00000000000
IMEI : 000000000000000

I have 4g connectivity issues especially on whats app (can only send text but can't send media), Facebook ( works for a while and then 4g stops working on it) , yahoo mail (won't refresh or open/send emails unless on wifi) , and linkden ( feed doesn't load unless on wifi), and youtube works with no issues.

This issue is killing me, how can I fix it? I live in the middle east (Jordan), does that effect anything ? I already factory reset my phone and re-installed all my programs, I got my SIM Card checked, I checked with my service provider and nothing is wrong.
Help! what can I do to fix my problem ?

Screenshot of download mode: imgur.COM/a/sJEWUA1
Screenshot of about phone screen : imgur.COM/a/aDlWRSc

Can you notice that it says on phone info its SM-935F but in download mode it says its Sm-935V