diff --git a/app.py b/app.py
index 8db9657..123d38b 100644
--- a/app.py
+++ b/app.py
@@ -1,4 +1,5 @@
 import json
+import traceback
 import uuid
 
 from flask import Flask, request, render_template_string
@@ -120,6 +121,7 @@ def tray_load():
         <p>Updated Spool ID {spool_id} with TAG id {tag_id} to AMS {ams_id}, Tray {tray_id}.</p>
         """
   except Exception as e:
+    traceback.print_exc()
     return f"<h1>Error</h1><p>{str(e)}</p>"
 
 
@@ -162,11 +164,12 @@ def home():
       <ul>
       """
     for spool in spools:
-      if not spool.get("extra", {}).get("tag"):
+      if not spool.get("extra", {}).get("tag") or spool.get("extra", {}).get("tag") == json.dumps(""):
         html += f"<li><a href='/assign_tag?spool_id={spool.get('id')}'>Spool {spool.get('filament').get('vendor').get('name')} - {spool.get('filament').get('name')}</a></li>"
     html += "</ul>"
     return html
   except Exception as e:
+    traceback.print_exc()
     return f"<h1>Error</h1><p>{str(e)}</p>"
 
 
@@ -189,12 +192,13 @@ def assign_tag():
         <script type="text/javascript">
         function writeNFC(){{
           const ndef = new NDEFReader();
+          document.getElementById("message").textContent="Bring NFC Tag closer to the phone.";
           ndef.write({{
             records: [{{ recordType: "url", data: "{BASE_URL}/spool_info?tag_id={myuuid}" }}],
           }}).then(() => {{
-            alert("Message written.");
+            document.getElementById("message").textContent="Message written.";
           }}).catch(error => {{
-            alert(`Write failed :-( try again: ${{error}}.`);
+            document.getElementById("message").textContent="Write failed :-( try again: " + error + ".";
           }}); 
         }};
         </script>
@@ -202,6 +206,7 @@ def assign_tag():
         <body>
         NFC Write
         <button id="write" onclick="writeNFC()">Write</button>
+        <h1 id="message"></h1>
         </body>
         </html>
         """
diff --git a/mqtt_bambulab.py b/mqtt_bambulab.py
index f52d35b..288db0a 100644
--- a/mqtt_bambulab.py
+++ b/mqtt_bambulab.py
@@ -31,7 +31,7 @@ def on_message(client, userdata, msg):
   # TODO: Consume spool
   try:
     data = json.loads(msg.payload.decode())
-    print(data)
+    #print(data)
     if "print" in data and "vt_tray" in data["print"]:
       print(data)
       LAST_AMS_CONFIG["vt_tray"] = data["print"]["vt_tray"]
@@ -79,15 +79,21 @@ def on_connect(client, userdata, flags, rc):
 
 
 def setActiveTray(spool_id, spool_extra, ams_id, tray_id):
-  patchExtraTags(spool_id, spool_extra, {
-    "active_tray": json.dumps(f"{PRINTER_ID}_{ams_id}_{tray_id}"),
-  })
+  if spool_extra == None:
+    spool_extra = {}
 
-  # Remove active tray from inactive spools
-  for old_spool in SPOOLS:
-    if spool_id != old_spool["id"] and old_spool["extra"]["active_tray"] == json.dumps(
-        f"{PRINTER_ID}_{ams_id}_{tray_id}"):
-      patchExtraTags(old_spool["id"], old_spool["extra"], {"active_tray": json.dumps("")})
+  if not spool_extra.get("active_tray") or spool_extra.get("active_tray") != json.dumps(f"{PRINTER_ID}_{ams_id}_{tray_id}"):
+    patchExtraTags(spool_id, spool_extra, {
+      "active_tray": json.dumps(f"{PRINTER_ID}_{ams_id}_{tray_id}"),
+    })
+
+    # Remove active tray from inactive spools
+    for old_spool in SPOOLS:
+      if spool_id != old_spool["id"] and old_spool["extra"]["active_tray"] == json.dumps(
+          f"{PRINTER_ID}_{ams_id}_{tray_id}"):
+        patchExtraTags(old_spool["id"], old_spool["extra"], {"active_tray": json.dumps("")})
+  else:
+    print("Skipping set active tray")
 
 
 # Fetch spools from spoolman
