The mysterious ways of Android

app/src/main/res/layout-w600dp-land/activity_view.xml

@@ -1,5 +1,4 @@
 <androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/drawer_layout"
     android:layout_width="match_parent"
@@ -13,10 +12,9 @@
 
         <FrameLayout
             android:id="@+id/content_frame"
-            android:layout_width="0dp"
+            android:layout_width="match_parent"
             android:layout_height="match_parent"
-            android:layout_weight="1"
-            app:layout_constraintEnd_toStartOf="@+id/content_separator" />
+            android:layout_weight="1" />
 
         <View
             android:id="@+id/content_separator"
@@ -26,7 +24,7 @@
 
         <FrameLayout
             android:id="@+id/content_pane"
-            android:layout_width="0dp"
+            android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:layout_weight="1" />
     </LinearLayout>