diff --git a/src/core/qgsmaplayer.cpp b/src/core/qgsmaplayer.cpp
index 2d2fd17af213..11e0058c8ef1 100644
--- a/src/core/qgsmaplayer.cpp
+++ b/src/core/qgsmaplayer.cpp
@@ -1970,7 +1970,7 @@ void QgsMapLayer::setLegend( QgsMapLayerLegend *legend )
   if ( mLegend )
   {
     mLegend->setParent( this );
-    connect( mLegend, &QgsMapLayerLegend::itemsChanged, this, &QgsMapLayer::legendChanged );
+    connect( mLegend, &QgsMapLayerLegend::itemsChanged, this, &QgsMapLayer::legendChanged, Qt::UniqueConnection );
   }
 
   emit legendChanged();
diff --git a/src/core/raster/qgsrasterlayer.cpp b/src/core/raster/qgsrasterlayer.cpp
index e114c2d6984d..a99fa8de2420 100644
--- a/src/core/raster/qgsrasterlayer.cpp
+++ b/src/core/raster/qgsrasterlayer.cpp
@@ -585,7 +585,7 @@ void QgsRasterLayer::init()
 {
   mRasterType = QgsRasterLayer::GrayOrUndefined;
 
-  setLegend( QgsMapLayerLegend::defaultRasterLegend( this ) );
+  whileBlocking( this )->setLegend( QgsMapLayerLegend::defaultRasterLegend( this ) );
 
   setRendererForDrawingStyle( QgsRaster::UndefinedDrawingStyle );
 
diff --git a/src/core/raster/qgsrasterpipe.cpp b/src/core/raster/qgsrasterpipe.cpp
index 3a91f11a46ae..4a742431c4a7 100644
--- a/src/core/raster/qgsrasterpipe.cpp
+++ b/src/core/raster/qgsrasterpipe.cpp
@@ -99,7 +99,11 @@ bool QgsRasterPipe::insert( int idx, QgsRasterInterface *interface )
     success = true;
     mInterfaces.insert( idx, interface );
     setRole( interface, idx );
-    QgsDebugMsgLevel( QStringLiteral( "inserted OK" ), 4 );
+    QgsDebugMsgLevel( QStringLiteral( "Pipe %1 inserted OK" ).arg( idx ), 4 );
+  }
+  else
+  {
+    QgsDebugMsgLevel( QStringLiteral( "Error inserting pipe %1" ).arg( idx ), 4 );
   }
 
   // Connect or reconnect (after the test) interfaces
@@ -152,7 +156,7 @@ Qgis::RasterPipeInterfaceRole QgsRasterPipe::interfaceRole( QgsRasterInterface *
   else if ( dynamic_cast<QgsRasterNuller *>( interface ) )
     role = Qgis::RasterPipeInterfaceRole::Nuller;
 
-  QgsDebugMsgLevel( QStringLiteral( "%1 role = %2" ).arg( typeid( *interface ).name() ).arg( qgsEnumValueToKey( role ) ), 4 );
+  QgsDebugMsgLevel( QStringLiteral( "%1 role = %2" ).arg( typeid( *interface ).name(), qgsEnumValueToKey( role ) ), 4 );
   return role;
 }
 
@@ -171,7 +175,21 @@ void QgsRasterPipe::unsetRole( QgsRasterInterface *interface )
   if ( role == Qgis::RasterPipeInterfaceRole::Unknown )
     return;
 
+  const int roleIdx{ mRoleMap[role] };
   mRoleMap.remove( role );
+
+  // Decrease all indexes greater than the removed one
+  const auto roleMapValues {mRoleMap.values()};
+  if ( roleIdx < *std::max_element( roleMapValues.begin(), roleMapValues.end() ) )
+  {
+    for ( auto it = mRoleMap.cbegin(); it != mRoleMap.cend(); ++it )
+    {
+      if ( it.value() > roleIdx )
+      {
+        mRoleMap[it.key()] = it.value() - 1;
+      }
+    }
+  }
 }
 
 bool QgsRasterPipe::set( QgsRasterInterface *interface )
@@ -300,11 +318,16 @@ bool QgsRasterPipe::remove( int idx )
     unsetRole( mInterfaces.at( idx ) );
     delete mInterfaces.at( idx );
     mInterfaces.remove( idx );
-    QgsDebugMsgLevel( QStringLiteral( "removed OK" ), 4 );
+    QgsDebugMsgLevel( QStringLiteral( "Pipe %1 removed OK" ).arg( idx ), 4 );
+  }
+  else
+  {
+    QgsDebugMsgLevel( QStringLiteral( "Error removing pipe %1" ).arg( idx ), 4 );
   }
 
   // Connect or reconnect (after the test) interfaces
   connect( mInterfaces );
+
   return success;
 }