diff --git a/app.py b/app.py
index 0084a48..f5b3517 100644
--- a/app.py
+++ b/app.py
@@ -82,6 +82,9 @@ COUNT_DEDUP_FRAMES = int(os.environ.get("COUNT_DEDUP_FRAMES", "12"))
 # unbegrenzte Wachsen der Zustaende (Speicherleck) und falsches Unterdruecken
 # bei spaeterer Track-ID-Wiederverwendung. Wert > Verweildauer eines Fahrzeugs.
 COUNT_FORGET_FRAMES = int(os.environ.get("COUNT_FORGET_FRAMES", "150"))
+# Diagnose: pro verarbeitetem Frame mit Fahrzeugen eine Log-Zeile ausgeben
+# (Bewegung? Detektionen? IDs? Abstand zur Linie? gezaehlt?). COUNT_DEBUG=1.
+COUNT_DEBUG = os.environ.get("COUNT_DEBUG", "0") == "1"
 
 # --- MQTT: ein Event pro Linienueberquerung (fuer n8n -> NocoDB) -----------
 # Komplett abschaltbar: MQTT_ENABLED=false -> App laeuft ohne Broker/Events.
@@ -356,6 +359,10 @@ def process_frame(frame, det_model, det_names, line_start, line_end, state, sour
         track_positions.pop(tid, None)
         counted_ids.discard(tid)
 
+    dbg_vehicles = 0
+    dbg_counted = 0
+    dbg_dists = []
+
     if results and results[0].boxes is not None and results[0].boxes.id is not None:
         boxes = results[0].boxes.xyxy.int().cpu().tolist()
         class_ids = results[0].boxes.cls.int().cpu().tolist()
@@ -368,6 +375,11 @@ def process_frame(frame, det_model, det_names, line_start, line_end, state, sour
             center_y = (y1 + y2) // 2
 
             if label_name in VEHICLE_CLASSES:
+                if COUNT_DEBUG:
+                    dbg_vehicles += 1
+                    dbg_dists.append(int(point_to_segment_dist(
+                        center_x, center_y,
+                        line_start[0], line_start[1], line_end[0], line_end[1])))
                 if track_id not in counted_ids:
                     crossed = False
 
@@ -395,6 +407,7 @@ def process_frame(frame, det_model, det_names, line_start, line_end, state, sour
                         types[label_name] += 1
                         publish_crossing(label_name, track_id, source)
                         cv2.circle(frame, (center_x, center_y), 25, (0, 255, 0), 5)
+                        dbg_counted += 1
 
                 track_positions[track_id] = (center_x, center_y, frame_idx)
 
@@ -407,6 +420,14 @@ def process_frame(frame, det_model, det_names, line_start, line_end, state, sour
             cv2.putText(frame, label, (x1, y1 - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 0, 255), 1)
             cv2.circle(frame, (center_x, center_y), 3, (0, 255, 255), -1)
 
+    if COUNT_DEBUG and dbg_vehicles:
+        print(
+            f"[count-debug] frame#{frame_idx} fahrzeuge={dbg_vehicles} "
+            f"abstand_zur_linie={sorted(dbg_dists)} band={COUNT_BAND_PX} "
+            f"jetzt_gezaehlt={dbg_counted} gesamt={state['count']}",
+            flush=True,
+        )
+
     return draw_overlay(frame, line_start, line_end, state)