With Doxygen 1.8.2, both the following work for me:
Using ///
/// This is an enum class
enum class fooenum {
FOO, ///< this is foo
BAR, ///< this is bar
};
Using /*! ... */
/*! This is an enum class */
enum class fooenum {
FOO, /*!< this is foo */
BAR, /*!< this is bar */
};


The doxygen changelog says that enum class is supported in Doxygen 1.8.2, so I suspect there may be some minor syntax issue in your commands. Could you please compare your commands with the above two snippets?
New features
Added support for C++11:
strongly typed enums, e.g.: enum class E