This problem is not caused by our servers serving different content to your IP, it’s your device connecting to the wrong IP address. It’s a DNS issue.
No, DNS cache can help but isn’t guaranteed to work. Your own computer doesn’t connect to our servers directly for DNS, and instead connects to a so-called DNS resolver, usually provided by your network administrator or ISP. The DNS resolver has it’s own cache, which typically cannot be cleared by you.
For more information about this, and workarounds, please see the article that @wackyblackie shared: