This xml works fine on Android studio emulators, but not on the physical device. I ask for help

<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="20dp"
    android:gravity="center"
    android:text="@string/Mensagem_Principal"
    android:textSize="30sp"
    android:textStyle="bold" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="10dp"
    android:gravity="center"
    tools:text="Selecione a Categoria:"
    android:textStyle="bold"/>



<ListView
    android:id="@+id/listviewCat"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:text="@string/Categoria"

    />