Samsung Galaxy Note 4 dual sim, model SM-N9100 SIM#2 not registering to any 2G network

[stanchevstan]

I bought 3 months ago Samsung Galaxy Note 4 dual SIM model SM-N9100 factory unlocked with Android version 5.0.1 but I have never had chance to have SIM 2 working, it is 2G network only. I tried everything posted - used different SIMs, used manual and automatic network search within different countries as USA, Canada, Iceland, Norway, Netherlands, Turkey, Bulgaria. I tried hard reset too. It seems it is software issue because after all of the attempts I got message on the phone "SIM registered" but actually was not able to make and receive calls. I don't want to root the phone and to send it back to Samsung dealers for wasting the time. Please assist if you have idea how to fix it.