I’m still messing around with my Caddyfile, so I do a fair bit of changes/restarts, and sometimes I run into “Started certificate maintenance routine”. From what I’ve been able to find it seems to just run for a few seconds, and then proceed with the startup, but mine seems to get stuck. I haven’t left it running for hours, but at least 15 minutes.
Reverting the Caddyfile makes Caddy run normally, and changing it again gets the same issue.