I can help you if you have the router username and password using teamviewer.
What I can do is to open ports and check your router if you have any feature unchecked or checked which should not be there. Got good knowledge at the most common routers, not on routers made specifically in your country.
Not going to bother writing 10000 words in trying to explain how to check your router
ps: there is another way to check if u have any problems with ur internet which is by using a VPN. i rec. ipvanish which i think has a 24 hour free version.
turn it on and play and see. it will help your computer by pass any vpn issues u have. try it