I noticed it as well. I first thought it was a result of using CDN services or recycled IP addresses, but gnu.org doesn't use a CDN, and its IPv4 and IPv6 are b

I noticed it as well. I first thought it was a result of using CDN services or recycled IP addresses, but gnu.org doesn't use a CDN, and its IPv4 and IPv6 are both served by Hurricane Electric, which never did any business in mainland China. Must be a bug.