Hello,a few weeks ago I bought s7 edge which was rooted(bought not new phone) ,I wanted to instal stock fw,I mean to delete that root.So I tried to factory reset,it didnt helped,and the phone started to lag,so I instaled 7.0 stock fw,everything works smooth now except that I cant call,or send text messages,it says not registered on network,on 6.0 everything was fine,so any ideas how can I fix this issue? my model number is SM-G935FD is there any chance that I could instal SM-G935F fw and thats why Ive got this problem?