s6 edge 3g network issue (mobile data)

sorry about my bad english..........samsung s6 edge (sm g925).slow browsing or does not work mobile data when using 3g mobile data .in 2g mobile data is ok.but issues with WCDMA. I flash two different firmwares but same problem .set APN manually. SAME PROBLEM.and i have same issues while making a call or sending a message...........its a hardware issue????? i need your help thanks in advance.............