How to Set Up a Proxy Server in Chrome – Step-by-Step Guide? or Why Isn’t My Proxy Server in Chrome W

Yo! Had this exact problem. Some proxies block sites randomly.

Try this:
1. Open Chrome, type chrome://settings/system in the address bar.
2. Disable "Use a proxy server" under "Open proxy settings."

If the sites work after, your proxy’s the issue. Could also try a VPN as an alternative—sometimes they play nicer with sites.