fix: an issue of established f-m connections being duplicated in the run time.

src/coreComponents/physicsSolvers/surfaceGeneration/SurfaceGenerator.cpp

@@ -468,6 +468,28 @@ void SurfaceGenerator::postRestartInitialization()
   } );
 }
 
+bool SurfaceGenerator::execute( real64 const time_n,
+                                real64 const dt,
+                                integer const cycleNumber,
+                                integer const GEOS_UNUSED_PARAM( eventCounter ),
+                                real64 const GEOS_UNUSED_PARAM( eventProgress ),
+                                DomainPartition & domain )
+{
+  solverStep( time_n, dt, cycleNumber, domain );
+  forDiscretizationOnMeshTargets( domain.getMeshBodies(), [&] ( string const &,
+                                                                MeshLevel & meshLevel,
+                                                                arrayView1d< string const > const & )
+  {
+    ElementRegionManager & elemManager = meshLevel.getElemManager();
+    SurfaceElementRegion & fractureRegion = elemManager.getRegion< SurfaceElementRegion >( this->m_fractureRegionName );
+
+    FaceElementSubRegion & fractureSubRegion = fractureRegion.getUniqueSubRegion< FaceElementSubRegion >();
+    // without the clear of the following two fields, the initial fracture's f-m connections will be replicated later
+    fractureSubRegion.m_recalculateConnectionsFor2dFaces.clear();
+    fractureSubRegion.m_newFaceElements.clear();
+  });
+  return false;
+}
 
 real64 SurfaceGenerator::solverStep( real64 const & time_n,
                                      real64 const & dt,

src/coreComponents/physicsSolvers/surfaceGeneration/SurfaceGenerator.hpp

@@ -85,11 +85,7 @@ class SurfaceGenerator : public PhysicsSolverBase
                         integer const cycleNumber,
                         integer const GEOS_UNUSED_PARAM( eventCounter ),
                         real64 const GEOS_UNUSED_PARAM( eventProgress ),
-                        DomainPartition & domain ) override
-  {
-    solverStep( time_n, dt, cycleNumber, domain );
-    return false;
-  }
+                        DomainPartition & domain ) override;
 
   virtual real64 solverStep( real64 const & time_n,
                              real64 const & dt,