Filament Action: Select field value missing from $data when using multiple()

Action::make('AddStudent')
    ->form([
    Select::make('student_id')
      ->label('Select Student')
      ->relationship(
         name: 'students',
         titleAttribute: 'name',
          modifyQueryUsing: fn($query) => $query->where('role', 'student')
      )
      ->searchable()
      ->preload()
      ->multiple()
      ->required(),
TextInput::make('enrolled_at')
      ->required()
      ])
      ->action(function (array $data) {
          dd($data);
      })