Thee is an annoying bug with the favorites in Rig MAnager. If I mark a rig as favorite and select another rig the star disappears. the bug has been there for a while now. Are Kemper people aware of it?
In case you haven't please update your software, as far as I know, we've fixed this issue some time ago.
I've updated not so long ago, when the Acoustic Simulator was added.
I'm using Rig Manager Version 3.0.126 (16325).