Upgrading from Flowable 6.4.2 to 6.6.0

I was previously running 6.4.2 on a testing server, upgraded from 6.4.1 (this was a simple drop in replacement).
I did a drop in replacement of 6.6.0 wars (and removed all of the 6.4.2 war files), and everything worked just fine.
I however can no longer see all of my previous models. Was there an upgrade step I missed? Or is there anyway
I can restore the old models?

No, if you kept pointing them to the same database, the models should be still there. The upgrade doesn’t delete any data. Are you sure it’s configured to the right database and it’s not using the default in-memory H2 database?

Yes. I am using the right database, I haven’t changed the application.properties config file I left in the the tomcat/lib directory.