All For Gardening: Quick question, why Croton plant sad? (South window, bright indirect sun ~8 hours a day, not overwatered, terrain almost dry, was fine and then lost 3 leaves in a day)

Quick question, why Croton plant sad? (South window, bright indirect sun ~8 hours a day, not overwatered, terrain almost dry, was fine and then lost 3 leaves in a day)