How strange. I would try removing the Padshop 2 library in Library Manager, load Cubase and open Padshop 2, close Cubase, then reinstall the Padshop 2 content (double click on one of the .vstsound files). Does that fix it?
If not, does the Padshop 2 library show in Padshop’s “Load Preset” window? If it does, the issue only affects Cubase’s media bay - in which case I would try resetting Cubase’s preferences.