starhub d-link modem to mi router via WAN port,
mi router to desktop PC via LAN port.
"starhub d-link modem to mi router via WAN port" - this will create another network within your network, also will surface the 'famous' double NAT problem.
There are ways to solve the problem, one way is to set the 2nd router to bridge mode.
My preferred way is not to use the WAN port on the mi router, i.e. connect starhub router to mi router using LAN port on the mi router.
Remember to disable DHCP on the mi router, and set mi router's LAN address manually to 192.168.0.2. In this configuration, mi router behaves like a switch + AP.