Note4 fails to optain IP address on wifi at work

Hi guys,

My stock note4 on 5.1.1 doesnt connect to the wifi at work on the 1st floor where my workstation is. It does connect easy on the ground floor.
My laptop and ASUS tablet connects easy on the work wifi.
As a result i have to bring my own MIFI device to connect over my own personal wifi contract with Telkom.

When i try connect on the work wifi it says "obtaining IP address", then says "failed". But i can connect when im on the ground floor.

It did the same even before i upgraded the firmware OTA at home.

What could be the problem?

PC not detecting my Note4

I unable to transfer files through PC as its not detecting. Used to work fine. I've tried using KIES and still doesn't work. Please advice.