Samsung Galaxy S4 — Whatsapp not working on Web

Hi
Good day, I was using whatsapp on my Samsung Galaxy S4 and also using its web version on laptop. Moved my laptop to work place and everything was fine since last 2 days my whatsapp web is unable to connect and the circle sign keep on circulating and the amazing thing is this, once i try to connect to web my whatsapp no longer works on phone as well. Unable to send or receive messages on phone whereas not connected to web as well. QR code get scanned but screen never appeared. Restart the phone and again I start receiving messages on phone but unable to get connected to web version.

I was using the same network (internet) before no new thing or changes being made to computer or internet or whatsoever by me. Was perfectly using this on the same laptop in home and even in office too but not working since last 2 days. I reinstalled whatsapp as well, restarted phone and computer several times but unable to connect to web?
Can somebody help me in that regard. May be somebody changed the office internet setting (how to check, if this happened as there are few other people working in office as well) or may be something else any opinions will be highly appreciated.

Thanks
Amer