Problem at routerboard 750Gl

Hi . I have problem with my routerboard 750Gl I use it to separate speed between me & my friends at same flat . but one of my friends who is running windows 10 pro can’t enter the log in page though all the others can do so . so can anyone tell me if he had problem like this

He must maybe clear his browser cache and try again.

Also check if his computer is getting a valid IP address, most probably the issue is with that pc and not the router