diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp
index f7651b97e6..0ec3138221 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.cpp
@@ -1096,6 +1096,7 @@ void RimSummaryCurve::fieldChangedByUi( const caf::PdmFieldHandle* changedField,
         m_yValuesSummaryAddress->setAddress( m_yValuesSummaryAddressUiField() );
 
         calculateCurveInterpolationFromAddress();
+        updateSourceSteppingAfterAddressChange();
 
         loadAndUpdate = true;
     }
@@ -1104,6 +1105,7 @@ void RimSummaryCurve::fieldChangedByUi( const caf::PdmFieldHandle* changedField,
         m_xValuesSummaryAddress->setAddress( m_xValuesSummaryAddressUiField() );
 
         calculateCurveInterpolationFromAddress();
+        updateSourceSteppingAfterAddressChange();
 
         loadAndUpdate = true;
     }
@@ -1205,6 +1207,8 @@ void RimSummaryCurve::selectYSummaryAddress()
             m_yValuesSummaryCase = curveSelection[0].summaryCaseY();
             m_yValuesSummaryAddress->setAddress( curveSelection[0].summaryAddressY() );
 
+            updateSourceSteppingAfterAddressChange();
+
             checkForMatchingCrossPlotTimeSteps();
             loadAndUpdateDataAndPlot();
         }
@@ -1241,6 +1245,8 @@ void RimSummaryCurve::selectXSummaryAddress()
             m_xValuesSummaryCase = curveSelection[0].summaryCaseY();
             m_xValuesSummaryAddress->setAddress( curveSelection[0].summaryAddressY() );
 
+            updateSourceSteppingAfterAddressChange();
+
             checkForMatchingCrossPlotTimeSteps();
             loadAndUpdateDataAndPlot();
         }
@@ -1324,6 +1330,18 @@ void RimSummaryCurve::loadAndUpdateDataAndPlot()
     dataChanged.send();
 }
 
+//--------------------------------------------------------------------------------------------------
+/// When the summary vector of this curve is changed, make sure the toolbar 'Step By' field stays
+/// consistent with the selected vector.
+//--------------------------------------------------------------------------------------------------
+void RimSummaryCurve::updateSourceSteppingAfterAddressChange()
+{
+    if ( auto summaryMultiPlot = firstAncestorOrThisOfType<RimSummaryMultiPlot>() )
+    {
+        summaryMultiPlot->updateStepDimensionFromCurves();
+    }
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.h b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.h
index 13ef31016a..1f139ab5a9 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.h
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryCurve.h
@@ -146,6 +146,8 @@ private:
     void calculateCurveInterpolationFromAddress();
     void calculateCurveTypeFromAddress();
 
+    void updateSourceSteppingAfterAddressChange();
+
     static void appendOptionItemsForSummaryAddresses( QList<caf::PdmOptionItemInfo>* options, RimSummaryCase* summaryCase );
 
 private:
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.cpp b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.cpp
index 2f617bd345..3aaf07a197 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.cpp
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.cpp
@@ -826,7 +826,7 @@ void RimSummaryMultiPlot::updateTimeAxisRangesFromFirstTimePlot()
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-void RimSummaryMultiPlot::setDefaultRangeAggregationSteppingDimension()
+RimSummaryDataSourceStepping::SourceSteppingDimension RimSummaryMultiPlot::calculateStepDimensionFromCurves()
 {
     RiaSummaryAddressAnalyzer analyzer;
 
@@ -879,7 +879,15 @@ void RimSummaryMultiPlot::setDefaultRangeAggregationSteppingDimension()
         stepDimension = RimSummaryDataSourceStepping::SourceSteppingDimension::BLOCK;
     }
 
-    m_sourceStepping->setStepDimension( stepDimension );
+    return stepDimension;
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void RimSummaryMultiPlot::setDefaultRangeAggregationSteppingDimension()
+{
+    m_sourceStepping->setStepDimension( calculateStepDimensionFromCurves() );
 
     // Previously, when the stepping dimension was set to 'well' for range aggregation, it was based on all wells. If one of the wells
     // had extreme values and was not visible, it would set the y-range to match the extreme value, making some curves invisible. We
@@ -1833,6 +1841,20 @@ void RimSummaryMultiPlot::updateStepDimensionFromDefault()
     m_sourceStepping->setStepDimension( m_defaultStepDimension() );
 }
 
+//--------------------------------------------------------------------------------------------------
+/// Recompute the source stepping dimension when a summary vector is selected by manipulation of a curve,
+/// so the toolbar 'Step By' field stays consistent with what the curves actually display.
+//--------------------------------------------------------------------------------------------------
+void RimSummaryMultiPlot::updateStepDimensionFromCurves()
+{
+    auto stepDimension = calculateStepDimensionFromCurves();
+
+    m_sourceStepping->setStepDimension( stepDimension );
+    m_defaultStepDimension = stepDimension;
+
+    RiuPlotMainWindowTools::refreshToolbars();
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.h b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.h
index 003a464ef1..c98600fc30 100644
--- a/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.h
+++ b/ApplicationLibCode/ProjectDataModel/Summary/RimSummaryMultiPlot.h
@@ -106,6 +106,7 @@ public:
 
     void storeStepDimensionFromToolbar();
     void updateStepDimensionFromDefault();
+    void updateStepDimensionFromCurves();
 
     void selectWell( QString wellName );
 
@@ -135,6 +136,8 @@ private:
     void computeAggregatedAxisRange();
     void updateSourceStepper();
 
+    RimSummaryDataSourceStepping::SourceSteppingDimension calculateStepDimensionFromCurves();
+
     void        updatePlotVisibility();
     void        setAutoValueStates();
     static void setAutoValueStatesForPlot( RimSummaryPlot* summaryPlot, bool isMinMaxOverridden, bool isAppearanceOverridden );