diff --git a/src/py_dvt_ate/app/dashboard/app.py b/src/py_dvt_ate/app/dashboard/app.py
index 7bfd933..02090f6 100644
--- a/src/py_dvt_ate/app/dashboard/app.py
+++ b/src/py_dvt_ate/app/dashboard/app.py
@@ -128,12 +128,31 @@ def get_or_create_server() -> SimulationServer:
     """
     global _simulation_server, _server_thread
 
-    # Return existing server if it's running AND responsive
-    if _simulation_server is not None and _simulation_server.is_running:
-        # Verify the server is actually responding (not a stale flag)
-        if _is_server_responsive():
+    # FIRST: Check if ports are already in use (regardless of singleton state)
+    # This catches orphan servers from previous processes (e.g., Docker restarts)
+    ports_in_use = _is_server_responsive()
+
+    if ports_in_use:
+        # Ports are in use - either our singleton or an orphan process
+        if _simulation_server is not None and _simulation_server.is_running:
+            # We have a reference - reuse it
             return _simulation_server
-        # Server flag says running but it's not responsive - clean up
+        else:
+            # Orphan server from previous process - wait for it to die
+            st.warning("Waiting for previous server to shut down...")
+            for _ in range(10):  # Wait up to 5 seconds
+                time.sleep(0.5)
+                if not _is_server_responsive():
+                    break
+            else:
+                st.error(
+                    "Port still in use. Please wait a moment and refresh, "
+                    "or restart the container."
+                )
+                st.stop()
+
+    # Clean up stale singleton reference if ports are free but singleton exists
+    if _simulation_server is not None and not ports_in_use:
         _simulation_server = None
         _server_thread = None