Unhappy [Q] Calls end after root! Need help ASAP!

Hey xda guys!

So basically my cousin just bought a SM-N9005 yesterday and today i rooted it. But after the phone was rooted it just suddenly hangs up after a minute or so! tried to unroot it using supersu and doing a soft reset but that didn't seem to work :/

You guys got any suggestions?

Btw its running Kitkat 4.4.2 XXEUND5 and we're located in denmark