1. Fixed IP is set in school. Please set it to automatically obtain IP in the TCP/IP4 protocol of local connection.

2. surf the internet on the home router. At this time, you don't need to use broadband dial-up internet repeatedly, just plug in the network cable or connect directly to WiFi.

3. Eliminate the possibility of using the router's anti-collision network to restrict your machine.

4. If the router is not applicable, but the "broadband connection" has a fault code through the optical cat, please consult the service provider.

Summary: Personally, I think it may be that you used a fixed IP when surfing the Internet in college, so when you go home, it is different from the existing router IP. Check Local Area Connection > Properties > Internet Protocol Version 4> Get IP address automatically.