iOS 8 phone call problem

Hey guys I was wondering if anyone has the following problem. Whenever someone calls me and I pick up there are a couple of seconds delay before the conversation can start.
Not sure if I explained it well (not a native speaker) but in other words for 1 or 2 seconds after I accept a call the phone continues ringing, which is kind of annoying .

 

I live in Europe, so my carrier is different, and forgot to say I've got a 5c. But I did not have such problems with iOS 7

 

I did an over the air update. I wonder if I should make a clear reinstall.

 

Not really but sounds like a plan Trying it right now
Edit: How to reset networking settings? Trough carrier options?

 

I tried it all, there seems to be a slight improvement, but still the delay is obvious :/