diff --git a/src/dpl/src/legalize_shift.cxx b/src/dpl/src/legalize_shift.cxx
index 5b23147389b..22cecd9c40c 100644
--- a/src/dpl/src/legalize_shift.cxx
+++ b/src/dpl/src/legalize_shift.cxx
@@ -120,10 +120,18 @@ bool ShiftLegalizer::legalize(DetailedMgr& mgr)
   outgoing_.resize(size);
   for (size_t i = 0; i < mgr.getNumSegments(); i++) {
     const int segId = mgr.getSegment(i)->getSegId();
+    const int rowId = mgr.getSegment(i)->getRowId();
+    const DbuY rowBottom{arch_->getRow(rowId)->getBottom()};
     for (size_t j = 1; j < mgr.getNumCellsInSeg(segId); j++) {
       const Node* prev = mgr.getCellsInSeg(segId)[j - 1];
       const Node* curr = mgr.getCellsInSeg(segId)[j];
 
+      // Only add edges from a cell's bottom (primary) row to avoid
+      // cycles in the topological sort caused by multi-height cells
+      // appearing in multiple row segments with conflicting orderings.
+      if (prev->getBottom() != rowBottom || curr->getBottom() != rowBottom) {
+        continue;
+      }
       incoming_[curr->getId()].push_back(prev->getId());
       outgoing_[prev->getId()].push_back(curr->getId());
     }
diff --git a/src/dpl/src/optimization/detailed_manager.h b/src/dpl/src/optimization/detailed_manager.h
index 9573bc41d76..3e36b76cac4 100644
--- a/src/dpl/src/optimization/detailed_manager.h
+++ b/src/dpl/src/optimization/detailed_manager.h
@@ -265,7 +265,10 @@ class DetailedMgr
     // Needs cell centers.
     bool operator()(Node* p, Node* q) const
     {
-      return p->getCenterX() < q->getCenterX();
+      if (p->getCenterX() != q->getCenterX()) {
+        return p->getCenterX() < q->getCenterX();
+      }
+      return p->getId() < q->getId();
     }
     bool operator()(Node*& s, DbuX i) const { return s->getCenterX() < i; }
     bool operator()(DbuX i, Node*& s) const { return i < s->getCenterX(); }