diff --git a/Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/CheckResidConfig.h b/Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/CheckResidConfig.h
index 53dffeed7ad69..2a07eaf87930f 100644
--- a/Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/CheckResidConfig.h
+++ b/Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/CheckResidConfig.h
@@ -26,11 +26,14 @@ struct CheckResidConfig : o2::conf::ConfigurableParamHelper<CheckResidConfig> {
 
   bool pvcontribOnly = true;
   bool addPVAsCluster = true;
-  bool refitPV = true;
   bool useStableRef = true;
   bool doIBOB = true;
   bool doResid = true;
 
+  bool refitPV = true;
+  float refitPVMV = false;
+  float refitPVIniScale = 100.f;
+
   O2ParamDef(CheckResidConfig, "checkresid");
 };
 } // namespace o2::checkresid
diff --git a/Detectors/GlobalTrackingWorkflow/study/src/CheckResid.cxx b/Detectors/GlobalTrackingWorkflow/study/src/CheckResid.cxx
index d665af5747c60..e6584a7055446 100644
--- a/Detectors/GlobalTrackingWorkflow/study/src/CheckResid.cxx
+++ b/Detectors/GlobalTrackingWorkflow/study/src/CheckResid.cxx
@@ -38,14 +38,17 @@
 #include "CommonUtils/TreeStreamRedirector.h"
 #include "ReconstructionDataFormats/VtxTrackRef.h"
 #include "DetectorsVertexing/PVertexer.h"
-
 #ifdef WITH_OPENMP
 #include <omp.h>
 #endif
 
+// Attention: in case the residuals are checked with geometry different from the one used for initial reconstruction,
+// pass a --configKeyValues option for vertex refit as:
+// ;pvertexer.useMeanVertexConstraint=false;pvertexer.iniScale2=100;pvertexer.acceptableScale2=10.;
+// In any case, it is better to pass ;pvertexer.useMeanVertexConstraint=false;
+
 namespace o2::checkresid
 {
-
 using namespace o2::framework;
 using DetID = o2::detectors::DetID;
 using DataRequest = o2::globaltracking::DataRequest;
@@ -83,6 +86,7 @@ class CheckResidSpec : public Task
 
   o2::globaltracking::RecoContainer* mRecoData = nullptr;
   int mNThreads = 1;
+  bool mMeanVertexUpdated = false;
   float mITSROFrameLengthMUS = 0.f;
   o2::dataformats::MeanVertexObject mMeanVtx{};
   std::vector<o2::BaseCluster<float>> mITSClustersArray;    ///< ITS clusters created in run() method from compact clusters
@@ -131,6 +135,7 @@ void CheckResidSpec::updateTimeDependentParams(ProcessingContext& pc)
   // mTPCCorrMapsLoader.extractCCDBInputs(pc);
   static bool initOnceDone = false;
   if (!initOnceDone) { // this params need to be queried only once
+    const auto& params = o2::checkresid::CheckResidConfig::Instance();
     initOnceDone = true;
     // Note: reading of the ITS AlpideParam needed for ITS timing is done by the RecoContainer
     auto grp = o2::base::GRPGeomHelper::instance().getGRPECS();
@@ -142,9 +147,13 @@ void CheckResidSpec::updateTimeDependentParams(ProcessingContext& pc)
     }
     auto geom = o2::its::GeometryTGeo::Instance();
     geom->fillMatrixCache(o2::math_utils::bit2Mask(o2::math_utils::TransformType::T2L, o2::math_utils::TransformType::L2G, o2::math_utils::TransformType::T2G));
-    o2::conf::ConfigurableParam::updateFromString("pvertexer.useMeanVertexConstraint=false");
+    o2::conf::ConfigurableParam::updateFromString("pvertexer.useTimeInChi2=false;");
     mVertexer.init();
   }
+  if (mMeanVertexUpdated) {
+    mMeanVertexUpdated = false;
+    mVertexer.initMeanVertexConstraint();
+  }
   bool updateMaps = false;
   /*
   if (mTPCCorrMapsLoader.isUpdated()) {
@@ -200,6 +209,7 @@ void CheckResidSpec::process()
     }
     nvGood++;
     if (params.refitPV) {
+      LOGP(debug, "Refitting PV#{} of {} tracks", iv, pve.getNContributors());
       auto tStartPVF = std::chrono::time_point_cast<std::chrono::microseconds>(std::chrono::system_clock::now()).time_since_epoch().count();
       bool res = refitPV(pve, iv);
       pvFitDuration += std::chrono::time_point_cast<std::chrono::microseconds>(std::chrono::system_clock::now()).time_since_epoch().count() - tStartPVF;
@@ -315,6 +325,7 @@ bool CheckResidSpec::processITSTrack(const o2::its::TrackITS& iTrack, const o2::
 
   resTrack.points.clear();
   if (!prop->propagateToDCA(pv, trFitOut, bz)) {
+    LOGP(debug, "Failed to propagateToDCA, {}", trFitOut.asString());
     return false;
   }
   float cosAlp, sinAlp;
@@ -418,7 +429,7 @@ bool CheckResidSpec::refitPV(o2::dataformats::PrimaryVertex& pv, int vid)
   std::vector<o2::track::TrackParCov> tracks;
   std::vector<bool> useTrack;
   std::vector<GTrackID> gidsITS;
-  int ntr = pv.getNContributors();
+  int ntr = pv.getNContributors(), ntrIni = ntr;
   tracks.reserve(ntr);
   useTrack.reserve(ntr);
   gidsITS.reserve(ntr);
@@ -447,20 +458,18 @@ bool CheckResidSpec::refitPV(o2::dataformats::PrimaryVertex& pv, int vid)
     ntr++;
   }
   if (ntr < params.minPVContributors || !mVertexer.prepareVertexRefit(tracks, pv)) {
+    LOGP(warn, "Abandon vertex refit: NcontribNew = {} vs NcontribOld = {}", ntr, ntrIni);
     return false;
   }
-  // readjust vertexZ
-  const auto& pool = mVertexer.getTracksPool();
-  float zUpd = 0;
-  for (const auto& t : pool) {
-    zUpd += t.z;
-  }
-  if (pool.size()) {
-    pv.setZ(zUpd / pool.size());
-    mVertexer.prepareVertexRefit(tracks, pv);
+  LOGP(debug, "Original vtx: Nc:{} {}, chi2={}", pv.getNContributors(), pv.asString(), pv.getChi2());
+  auto pvSave = pv;
+  pv = mVertexer.refitVertexFull(useTrack, pv);
+  LOGP(debug, "Refitted vtx: Nc:{} {}, chi2={}", ntr, pv.asString(), pv.getChi2());
+  if (pv.getChi2() < 0.f) {
+    LOGP(warn, "Failed to refit PV {}", pvSave.asString());
+    return false;
   }
-  pv = mVertexer.refitVertex(useTrack, pv);
-  return pv.getChi2() > 0.f;
+  return true;
 }
 
 bool CheckResidSpec::refitITStrack(o2::track::TrackParCov& track, GTrackID gid)
@@ -515,6 +524,7 @@ void CheckResidSpec::finaliseCCDB(ConcreteDataMatcher& matcher, void* obj)
   if (matcher == ConcreteDataMatcher("GLO", "MEANVERTEX", 0)) {
     LOG(info) << "Imposing new MeanVertex: " << ((const o2::dataformats::MeanVertexObject*)obj)->asString();
     mMeanVtx = *(const o2::dataformats::MeanVertexObject*)obj;
+    mMeanVertexUpdated = true;
     return;
   }
   if (matcher == ConcreteDataMatcher("ITS", "CLUSDICT", 0)) {
diff --git a/Detectors/Vertexing/include/DetectorsVertexing/PVertexer.h b/Detectors/Vertexing/include/DetectorsVertexing/PVertexer.h
index 9967cbfcd5642..c06c2119b0cd1 100644
--- a/Detectors/Vertexing/include/DetectorsVertexing/PVertexer.h
+++ b/Detectors/Vertexing/include/DetectorsVertexing/PVertexer.h
@@ -113,7 +113,7 @@ class PVertexer
   bool prepareVertexRefit(const TR& tracks, const o2d::VertexBase& vtxSeed);
 
   PVertex refitVertex(const std::vector<bool> useTrack, const o2d::VertexBase& vtxSeed);
-
+  PVertex refitVertexFull(const std::vector<bool> useTrack, const o2d::VertexBase& vtxSeed);
   auto getNTZClusters() const { return mNTZClustersIni; }
   auto getTotTrials() const { return mTotTrials; }
   auto getMaxTrialsPerCluster() const { return mMaxTrialPerCluster; }
@@ -135,6 +135,7 @@ class PVertexer
   void setPoolDumpDirectory(const std::string& d) { mPoolDumpDirectory = d; }
 
   void printInpuTracksStatus(const VertexingInput& input) const;
+  void initMeanVertexConstraint();
 
  private:
   static constexpr int DBS_UNDEF = -2, DBS_NOISE = -1, DBS_INCHECK = -10;
@@ -152,7 +153,6 @@ class PVertexer
   FitStatus evalIterations(VertexSeed& vtxSeed, PVertex& vtx) const;
   TimeEst timeEstimate(const VertexingInput& input) const;
   float findZSeedHistoPeak() const;
-  void initMeanVertexConstraint();
   void applyConstraint(VertexSeed& vtxSeed) const;
   bool upscaleSigma(VertexSeed& vtxSeed) const;
   bool relateTrackToMeanVertex(o2::track::TrackParCov& trc, float vtxErr2);
diff --git a/Detectors/Vertexing/src/PVertexer.cxx b/Detectors/Vertexing/src/PVertexer.cxx
index 5fea1943ac762..10e504bba0772 100644
--- a/Detectors/Vertexing/src/PVertexer.cxx
+++ b/Detectors/Vertexing/src/PVertexer.cxx
@@ -1333,6 +1333,37 @@ PVertex PVertexer::refitVertex(const std::vector<bool> useTrack, const o2d::Vert
   return vtxRes;
 }
 
+//______________________________________________
+PVertex PVertexer::refitVertexFull(const std::vector<bool> useTrack, const o2d::VertexBase& vtxSeed)
+{
+  // Use this method if because of e.g. different alingnment the new vertex is supposed to be shifted from the original one.
+  // Refit the tracks prepared by the successful prepareVertexRefit, possible skipping those tracks wich have useTrack value false
+  // (useTrack is ignored if empty).
+  // The vtxSeed is the originally found vertex, assumed to be the same original PV used for the prepareVertexRefit.
+  // Refitted PrimaryVertex is returned, negative chi2 means failure of the refit.
+  // ATTENTION: only the position is refitted, the vertex time and IRMin/IRMax info is dummy.
+
+  if (vtxSeed != mVtxRefitOrig) {
+    throw std::runtime_error("refitVertex must be preceded by successful prepareVertexRefit");
+  }
+  VertexingInput inp;
+  inp.scaleSigma2 = mPVParams->iniScale2;
+  inp.idRange = gsl::span<int>(mRefitTrackIDs);
+  if (useTrack.size()) {
+    for (uint32_t i = 0; i < mTracksPool.size(); i++) {
+      mTracksPool[i].vtxID = useTrack[mTracksPool[i].entry] ? TrackVF::kNoVtx : TrackVF::kDiscarded;
+    }
+  }
+  PVertex vtxRes{};
+  vtxRes.VertexBase::operator=(vtxSeed);
+  if (findVertex(inp, vtxRes)) {
+    vtxRes.setTimeStamp({0.f, -1.}); // time is not refitter
+  } else {
+    vtxRes.setChi2(-1.);
+  }
+  return vtxRes;
+}
+
 //______________________________________________
 void PVertexer::printInpuTracksStatus(const VertexingInput& input) const
 {