It's hard to say with just this info, but I can tell you what has saved me a few times.
Logrotate has a debug option that will print a play-by-play of each step it takes to stdout. So in this case you could do:
logrotate -d /etc/logrotate.conf
logrotate -d /etc/logrotate.conf The output will tell you what exactly is going on. Also, if you want to narrow down the debug output you can do
logrotate -d /etc/logrotate.d/messages
logrotate -d /etc/logrotate.d/messages Though you may want to temporarily place the main logrotate.conf options in that files block since specifying the file directly means it will have never read the main configs options. Specifying the individual file also means you can use the -f-f (force) option in combination with the debug option to get a look at an actual rotation of the messages file taking place.