Problem with internet connection

Hello. I have a zyxel router model VMG8623-T50B and I face the following problem. Despite being connected to the internet, one computer (UBUNTU Linux OS) has no problem with applications connecting to internet, while, in my Windows PC, applications such as AnyDesk cannot connect to the internet. The same thing happens to a variety of sites. Internet Connection exists, but certain sites can not be visited. How can I solve the problem?

Thanks in advance