China Blocks Tumblr Custom Domains

The custom domains for my Tumblr blogs don’t work in China.

You can access Tumblr’s homepage, the Tumblr dashboard, and any sites with .tumblr.com in the address from mainland China without a VPN or proxy. But, for some reason, once a Tumblr site is given a custom domain, it no longer works.

In my case, willmoyer.com works, willmoyer.tumblr.com works, but once I made blog.willmoyer.com the domain for my Tumblr it stopped working. I’ve noticed similar behavior among other sites once assigned a custom domain.

I’m writing this hoping that some Tumblr user out there has experienced this and can help. Any ideas?