Default [Q] Mobile data connection problem

Hi

I was wondering if i can find help here as all other sources failed
I will try to describe problem as detailed as possible but I'm newb when it comes to android so please be understanding

I'm Samsung Galaxy S4 user, just stock model I9505 running Android 4.4.2.
Using WiFi phone is completely fine but when it comes to mobile data there comes the problem..

I can use internet, browse small websites or use hangouts/fb messanger but i it seems outgoing connection is slow or none.
It happens at random and can last for 1 or more hours.
When i take seedtest, download is fine at 4Mbps but when it gets to upload app stops until <force close>.

Something is wrong with outgoping bandwith.. Ive tried to set up APN manually, restart, clear cache etc nothing works.
Ive been on the phone with operator and they said its all fine on their end.

I'm on unlimited Tmobile 3g tariff.


Anyone faced similar problem or knows how to solve it?
i appreciate any help