Get 850MHz 3G working on Samsung S5 Active

I have Samsung S5 Active. It seems that it never get the 3G signal, only 2G. After some research I found that 850Mhz is disabled in my phone, I tried to enabled it with the code: *#197328640# but no luck. This code seems to work only with S5 but not with S5 Active. I don't have even DEBUG SCREEN menu if I enter this code. Any suggestion how can I enable 850 3G in my phone? I also tried to connect to my phone from terminal: $ adb shell shell@android:/ $ am start -n com.android.settings/.BandMode After entering these commands, I got to the menu in my phone: Set GSM/UMTS Band: but there were no options to chose. I believe somehting is blocking me from changing the band. Please help, I can't use 3G until I fix it, it seems that mine other chinese phone works much better than Samsung S5 Active.