Yeah, if you’ve imported the virtualmin.tar.gz file, that imports your previous Virtualmin settings. The first-time wizard won’t run then, since your previous Virtualmin settings specify that it already ran.
Regarding your logs – migrating to a new server shouldn’t affect that.
If you manually look at one of those files, are they blank or non-existent? The file “/var/log/messages” I believe is used on all distros supported by Virtualmin.