Android : Actionbar button not showing on some (LG) devices

following issue one only some LG devices:

Action Buttons are not displaying, items are also not swapped to overflow menu. Overflow menu has normal amout of entries as specified. Looks like the button reserves space but does not draw.

On one device I see the buttons flickers in and out when clicking on overflow button.

And one device has the overflow button drawn in the middle of actionbar in landscape mode.

Same behavior in portrait or landscape mode.

I tested on several LG devices. With other brands it always seems okay. These have the problem:

-lg g pad 8.3 Android 4.4.2

-LG G2 4.4.2

-LG G Flex 4.4.2

These devices are okay:

-LG g3 4.4.2

-LG Optimus 4X HD P880

-LG Optimus L5 E610 Android 4.0.3

-LG nexus 5

My menu:

    <item
        android:id="@+id/menu1"
        android:icon="@drawable/ic_action_back"
        android:showAsAction="always"
        android:title="@string/str1"/>
    <item
        android:id="@+id/menu2"
        android:icon="@drawable/ic_action_view_as_grid"
        android:showAsAction="always"
        android:title="@string/menu_fragen_navigation"/>
    <item
        android:id="@+id/menu3"
        android:icon="@drawable/ic_action_cancel"
        android:showAsAction="always"
        android:title="@string/str2"/>
    <item
        android:id="@+id/menu4"
        android:icon="@drawable/ic_action_info"
        android:showAsAction="ifRoom"
        android:title="@string/str3"/>
    <item
        android:id="@+id/menu4"
        android:icon="@drawable/ic_menu_mark"
        android:showAsAction="ifRoom"
        android:title="@string/str4"/>
    <item
        android:id="@+id/menu5"
        android:icon="@drawable/ic_menu_notifications"
        android:showAsAction="always"
        android:title="@string/str5"/>
    <item
        android:id="@+id/menu6"
        android:icon="@drawable/ic_action_forward"
        android:showAsAction="always"
        android:title="@string/str6"/>
    <item
        android:id="@+id/menu7"
        android:showAsAction="never"
        android:enabled="false"
        android:title="@string/str7"/>
    <item
        android:id="@+id/menu8"
        android:showAsAction="never"
        android:title="@string/str8"/>
    <item
        android:id="@+id/menu9"
        android:showAsAction="never"
        android:title="@string/str9"/>
    <item
        android:id="@+id/menu10"
        android:showAsAction="never"
        android:title="@string/str10"/>

</menu>