cTrader Desktop work at home but not at my workplace

Hi, I use a Laptop at home and everything works fine, but If I use my Laptop at my workplace with other internet connection it doesnt load the chats. I see only white space and hourglass instead of the charts.  Everything, including my account is displayed correctly except the charts. It doesnt matter if its Ethernet or W-Lan, as soon as I´m at my workspace the charts doesnt load anymore.

It seems there is an internet authorization problem or something else. How can I fix that?

Thank you very much! Cheers

Robert

PS: (cTrader Web works fine everywhere)