diff --git a/src/slic3r/GUI/FilamentGroupPopup.hpp b/src/slic3r/GUI/FilamentGroupPopup.hpp
index 09b6b8d344..e50c04317f 100644
--- a/src/slic3r/GUI/FilamentGroupPopup.hpp
+++ b/src/slic3r/GUI/FilamentGroupPopup.hpp
@@ -29,6 +29,7 @@ public:
     FilamentGroupPopup(wxWindow *parent);
     void tryPopup(Plater* plater,PartPlate* plate, bool slice_all);
     void tryClose();
+    void Dismiss() override;
 
     FilamentMapMode GetSelectedMode() const { return m_mode; }
 private:
@@ -40,7 +41,6 @@ private:
     void OnLeaveWindow(wxMouseEvent &);
     void OnEnterWindow(wxMouseEvent &);
     void OnTimer(wxTimerEvent &event);
-    void Dismiss();
 
     void CreateBmps();
 
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index 84b702d7e5..bb5ffc87de 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -2309,6 +2309,12 @@ wxBoxSizer* MainFrame::create_side_tools()
 
             bool slice = true;
 
+            // The Slice-plate hover popup is a transient popup that keeps grabbing
+            // the mouse capture while shown. Left behind the modal grouping dialog it
+            // would starve that dialog of mouse events, so close it synchronously first.
+            if (m_filament_group_popup)
+                m_filament_group_popup->Dismiss();
+
             auto curr_plate = m_plater->get_partplate_list().get_curr_plate();
             #ifdef __linux__
                 PresetBundle* preset = wxGetApp().preset_bundle;