diff --git a/src/slic3r/GUI/Widgets/DropDown.cpp b/src/slic3r/GUI/Widgets/DropDown.cpp
index 59832067c8..d698f9f7dc 100644
--- a/src/slic3r/GUI/Widgets/DropDown.cpp
+++ b/src/slic3r/GUI/Widgets/DropDown.cpp
@@ -563,6 +563,34 @@ void DropDown::messureSize()
         subDropDown->text_off          = text_off;
         subDropDown->use_content_width = true;
         subDropDown->Create(GetParent());
+#ifdef __WXGTK__
+        // Orca:  Keep the wx parent as the combobox so wxPopupTransientWindow installs
+        // its capture handlers on the main dropdown, but make the native GTK
+        // popup transient for the currently open popup to satisfy Wayland's
+        // xdg-shell rule that a popup's parent must be the topmost mapped popup.
+        gtk_window_set_transient_for(GTK_WINDOW(subDropDown->GetHandle()), GTK_WINDOW(GetHandle()));
+        // Orca: On Wayland, while the sub holds an xdg_popup grab, motion events for
+        // the cursor over main may not be delivered (Mutter drops motion
+        // outside the grabbing surface). Poll on idle and synthesize a
+        // mouseMove on main so its hover highlight tracks and it can dismiss
+        // the sub when the cursor leaves the parent (group) item.
+        DropDown* sub = subDropDown;
+        sub->Bind(wxEVT_IDLE, [sub](wxIdleEvent& e) {
+            e.Skip();
+            if (!sub->IsShown() || !sub->mainDropDown->IsShown())
+                return;
+            wxPoint screen_pt = wxGetMousePosition();
+            if (sub->GetScreenRect().Contains(screen_pt) || !sub->mainDropDown->GetScreenRect().Contains(screen_pt))
+                return;
+            wxPoint main_pt = sub->mainDropDown->ScreenToClient(screen_pt);
+            wxMouseEvent ev(wxEVT_MOTION);
+            ev.SetEventObject(sub->mainDropDown);
+            ev.m_x = main_pt.x;
+            ev.m_y = main_pt.y;
+            sub->mainDropDown->mouseMove(ev);
+            e.RequestMore();
+        });
+#endif
         subDropDown->Bind(wxEVT_COMBOBOX, [this](wxCommandEvent &e) {
             e.SetEventObject(this);
             e.SetId(GetId());
@@ -759,6 +787,15 @@ void DropDown::Dismiss()
     PopupWindow::Dismiss();
 }
 
+bool DropDown::ShouldDismissOnTopWindowDeactivate()
+{
+    // On Wayland, mapping a chained xdg_popup with grab makes the parent
+    // toplevel inactive, which would otherwise cascade-dismiss the whole
+    // chain. Skip when our chain peer is shown.
+    return !((mainDropDown && mainDropDown->IsShown()) ||
+             (subDropDown  && subDropDown->IsShown()));
+}
+
 void DropDown::OnDismiss()
 {
     if (mainDropDown) {
diff --git a/src/slic3r/GUI/Widgets/DropDown.hpp b/src/slic3r/GUI/Widgets/DropDown.hpp
index 8b7ab19d61..639a13e526 100644
--- a/src/slic3r/GUI/Widgets/DropDown.hpp
+++ b/src/slic3r/GUI/Widgets/DropDown.hpp
@@ -110,6 +110,8 @@ protected:
 
     void OnDismiss() override;
 
+    bool ShouldDismissOnTopWindowDeactivate() override;
+
 private:
     void paintEvent(wxPaintEvent& evt);
     void paintNow();
diff --git a/src/slic3r/GUI/Widgets/PopupWindow.cpp b/src/slic3r/GUI/Widgets/PopupWindow.cpp
index a8412bcfc9..8fb1cda774 100644
--- a/src/slic3r/GUI/Widgets/PopupWindow.cpp
+++ b/src/slic3r/GUI/Widgets/PopupWindow.cpp
@@ -86,7 +86,8 @@ void PopupWindow::OnMouseEvent2(wxMouseEvent &evt)
 void PopupWindow::topWindowActiavate(wxActivateEvent &event)
 {
     event.Skip();
-    if (!event.GetActive() && IsShown()) DismissAndNotify();
+    if (!event.GetActive() && IsShown() && ShouldDismissOnTopWindowDeactivate())
+        DismissAndNotify();
 }
 #endif
 
diff --git a/src/slic3r/GUI/Widgets/PopupWindow.hpp b/src/slic3r/GUI/Widgets/PopupWindow.hpp
index 55231accce..45afea8213 100644
--- a/src/slic3r/GUI/Widgets/PopupWindow.hpp
+++ b/src/slic3r/GUI/Widgets/PopupWindow.hpp
@@ -17,6 +17,12 @@ public:
 #ifdef __WXMSW__
     void BindUnfocusEvent();
 #endif
+protected:
+    // Orca: Hook so derived classes (e.g. DropDown chains) can skip auto-dismissal
+    // when the toplevel deactivates as a side effect of their own popup grab
+    // (notably on Wayland, where mapping a chained xdg_popup with grab makes
+    // the parent toplevel briefly inactive).
+    virtual bool ShouldDismissOnTopWindowDeactivate() { return true; }
 private:
 #ifdef __WXOSX__
     void OnMouseEvent2(wxMouseEvent &evt);