For anybody using Quad9 9.9.9.9 & 149.112.112.112 #DNS for malware blocking: The c.im Mastodon server is not getting resolved.
At least for my location in North Central Florida, USA. Happened both in Fedilab on Android & Firefox.
Switching to 1.1.1.2 Cloudflare malware blocking DNS resolves fine. Don't know if it's due to Quad9 misconfiguration or if Quad9 incorrectly blocking c.im as malware/phishing.
Repost from my @markxs acct