diff --git a/src/ui/windows/shield_dialog.cpp b/src/ui/windows/shield_dialog.cpp
index 1f88b6c..79172d3 100644
--- a/src/ui/windows/shield_dialog.cpp
+++ b/src/ui/windows/shield_dialog.cpp
@@ -720,7 +720,14 @@ void ShieldDialog::render(App* app)
                                std::max(1, p.batchesEstimated), p.notesMerged);
             wrappedCaption(material::OnSurfaceMedium(), cap);
             if (!p.stopping) {
-                if (const char* key = services::runWaitKey(run.lastWait())) wrappedCaption(material::OnSurfaceMedium(), TR(key));
+                // The pause notice (waiting for a batch gap / sync / a send) toggles on and off every batch.
+                // Reserve a fixed two-line slot for it so its coming and going doesn't change the content
+                // height and make the auto-height, vertically-centred modal jump around during the run.
+                const float waitTop = ImGui::GetCursorPosY();
+                if (const char* key = services::runWaitKey(run.lastWait()))
+                    wrappedCaption(material::OnSurfaceMedium(), TR(key));
+                const float waitSlotH = ImGui::GetTextLineHeightWithSpacing() * 2.0f;
+                if (ImGui::GetCursorPosY() < waitTop + waitSlotH) ImGui::SetCursorPosY(waitTop + waitSlotH);
             }
         }
         ImGui::ProgressBar(static_cast<float>(p.batchesDone) / static_cast<float>(std::max(1, p.batchesEstimated)),
@@ -765,9 +772,20 @@ void ShieldDialog::render(App* app)
             }
         }
         ImGui::EndChild();
-        if (leftovers) {
-            ImGui::Spacing();
-            wrappedCaption(material::OnSurfaceMedium(), TR("merge_keep_each_run_again"));
+        {
+            // The "run again" hint appears partway through a run (once an address has leftover notes). While
+            // the run is live, reserve its measured height up front so it appearing doesn't shift the modal.
+            const float loTop = ImGui::GetCursorPosY();
+            if (leftovers) {
+                ImGui::Spacing();
+                wrappedCaption(material::OnSurfaceMedium(), TR("merge_keep_each_run_again"));
+            }
+            if (live) {
+                const float loH = ImGui::GetStyle().ItemSpacing.y +
+                                  ImGui::CalcTextSize(TR("merge_keep_each_run_again"), nullptr, false,
+                                                      ImGui::GetContentRegionAvail().x).y;
+                if (ImGui::GetCursorPosY() < loTop + loH) ImGui::SetCursorPosY(loTop + loH);
+            }
         }
         if (!live) {   // below the rows: merge_keep_each_some_failed says "see the list above"
             std::string endLine;