RSS not resolving

I run a website at http://www.thefluiddruid.com and I’m having a problem with my incoming rss feeds.

Here is the error:
RSS Error: WP HTTP Error: 0: php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution

I haven’t changed anything, and I run my own VPS and nothing changed there.
It was working fine, but started throwing the error a few days ago.

Any ideas?