Can not use enum (class) as slot argument with underlying type (unsigned) long, e.g. std::uint64_t

/usr/include/qt6/QtCore/qdatastream.h:421:12: error: use of overloaded operator '<<' is ambiguous (with operand types 'QDataStream' and 'typename std::underlying_type<EnumClassUsingUnsignedLong>::type' (aka 'long'))
{ return s << static_cast<typename std::underlying_type<T>::type>(t); }
 ~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/qt6/QtCore/qmetatype.h:2435:10: note: in instantiation of function template specialization 'operator<<<QtGui::EnumClassUsingUnsignedLong>' requested here
 \{ ds << *reinterpret_cast<const T *>(a); }
 ^
/usr/include/qt6/QtCore/qmetatype.h:2534:56: note: in instantiation of member function 'QtPrivate::QDataStreamOperatorForType<QtGui::EnumClassUsingUnsignedLong, true>::dataStreamOut' requested here
 /*.dataStreamOut=*/ QDataStreamOperatorForType<T>::dataStreamOut,
 ^
/usr/include/qt6/QtCore/qmetatype.h:2645:39: note: in instantiation of static data member 'QtPrivate::QMetaTypeForType<QtGui::EnumClassUsingUnsignedLong>::metaType' requested here
 return &QMetaTypeForType<Ty>::metaType;