I see two kinds of presets: factory and other. When I click a non-factory preset all works fine. When I click a factory preset, all the sounds are the same. Occasionally the first selected factory preset will load. But it then becomes the only factory preset; clicking other factory presets does nothing. I don't seem to see this odd and frustrating behavior with the other instruments included in MiniLab, only the Mini V (though if I looked very carefully perhaps I might see problems elsewhere much less often than with Mini V). I've re-installed the latest version of MiniLab (which includes Analog Lab and therefore Mini V) but nothing improved.
I'm running in Demo mode because MiniLab seems to have unauthorized itself. I can't reauthorize because my license has already been used. I'm waiting for a response to a support request. I assume that the fact that I'm running in Demo mode should have no bearing on the behavior of presets, especially the Mini V presets only.
P.S. More thorough investigation reveals that I do not seem to see the problem with the Modular or Wurlitzer but I do see the problem with other synths. So the problem affects the Mini but not only the Mini.
P.P.S. Arturia resolved my authorization problem promptly. When I activated (more accurately, re-activated) MiniLab the anomalies described above ceased to occur. The problem being solved, I might delete this posting but it seems better to leave it as bread crumbs for anyone else who experiences a similar problem.