Minecraft seems to block on SRV record requests when pinging or connecting to any server. My router times out on all SRV requests, causing a huge delay in refreshing servers and a 10 second freeze when connecting to one. This is probably a bug in the router, but it seems to be a common issue with cheap home routers and Minecraft could probably handle it better. At the very least, it could give some explicit feedback that there is a problem with SRV requests.

A workaround is to set DNS servers on your computer and not use the DNS cache on the router.