In China, Facebook cannot be used.
Google also cannot be used.

If you only access the Facebook page itself, you can use a VPN.
However, if a website embeds a Facebook plugin, it seems to exhibit strange behavior.

I entered China on April 12th.

Initially, the behavior was simply a timeout.
If a website contains a Google or Facebook plugin (such as a button), it fails to load properly, causing a timeout after waiting for several minutes before the page finally displays.

At first, I just ignored it because it was simply a connection issue that caused slowness.

However, on April 27th, websites that use Facebook started redirecting to strange pages (laugh).

I was redirected to a strange page such as http://wpkg.org/.

Even if it's just slow, being redirected to a strange page is a problem, so I immediately removed the Facebook plugin.
I also removed Google.

China is truly a strange place.

It seems that this issue affects not all of China, but specifically those using the Unicom provider. Currently, it may only affect Unicom, but it may spread to other providers, and there is also information that the redirection may occur to pages other than the one mentioned above.

It's unclear whether the Chinese government is behind this, or if it's simply that Unicom's DNS (the function that resolves hostnames) has been hacked.

When I searched, it seems that this issue is occurring not only in Luoyang, where I am, but also in Shanghai and other parts of China.

The only solutions seem to be to review your PC settings or, if you want to show it to a large number of people, to avoid using Facebook/Google.

Doing business with China is difficult... especially when it comes to networks. You never know what might happen.