material_design_icons_flutter ^4.0.5955 doesn't show the icons

Question

here is my code

Align(
                          alignment: Alignment.centerRight,
                          child: Tab(icon: Icon(Icons.sms_outlined))),
                      Tab(icon: Icon(MdiIcons.rocket)),

but it shows nothing:

instead, Icons shows normally : here is the code

Align(
                        alignment: Alignment.centerLeft,
                        child: Tab(
                          icon: Icon(Icons.person_outline),
                        ),
                      ),

the image of a normal icon :