i think it worked

app.py

@@ -3,7 +3,6 @@ import paho.mqtt.client as mqtt
 import queue, json, base64, io, os
 from PIL import Image
 
-@st.cache_resource
 def create_paho_client(tls=True):
     client = mqtt.Client(client_id="", userdata=None, protocol=mqtt.MQTTv5)
     if tls:
@@ -41,13 +40,14 @@ st.markdown("""
     This app is a public demo of ...
 """)
 
+# Checkbox to use own credentials
 use_own_creds = st.checkbox("Use your own credentials", value=False)
 
 if use_own_creds:
     HIVEMQ_USERNAME = st.text_input("HIVEMQ Username", type="password")
     HIVEMQ_PASSWORD = st.text_input("HIVEMQ Password", type="password")
-    HIVEMQ_HOST = st.text_input("HIVEMQ Host", type="password")
-    DEVICE_ID = st.text_input("Device ID", type="password")
+    HIVEMQ_HOST = st.text_input("HIVEMQ Host")
+    DEVICE_ID = st.text_input("Device ID")
     PORT = st.number_input("Port", min_value=1, step=1, value=8883)
 else:
     HIVEMQ_USERNAME = os.environ.get("HIVEMQ_USERNAME")
@@ -56,7 +56,7 @@ else:
     DEVICE_ID = os.environ.get("DEVICE_ID")
     PORT = int(os.environ.get("PORT", 8883))
 
-# Initialize or update the MQTT client and response queue in session state
+# Initialize st.session_state variables if not already initialized
 if 'client' not in st.session_state:
     st.session_state['client'] = None
     st.session_state['response_queue'] = None
@@ -66,32 +66,6 @@ if 'client' not in st.session_state:
     st.session_state['DEVICE_ID'] = None
     st.session_state['PORT'] = None
 
-credentials_changed = (
-    st.session_state['HIVEMQ_USERNAME'] != HIVEMQ_USERNAME or
-    st.session_state['HIVEMQ_PASSWORD'] != HIVEMQ_PASSWORD or
-    st.session_state['HIVEMQ_HOST'] != HIVEMQ_HOST or
-    st.session_state['DEVICE_ID'] != DEVICE_ID or
-    st.session_state['PORT'] != PORT
-)
-
-if st.session_state['client'] is None or credentials_changed:
-    st.session_state['HIVEMQ_USERNAME'] = HIVEMQ_USERNAME
-    st.session_state['HIVEMQ_PASSWORD'] = HIVEMQ_PASSWORD
-    st.session_state['HIVEMQ_HOST'] = HIVEMQ_HOST
-    st.session_state['DEVICE_ID'] = DEVICE_ID
-    st.session_state['PORT'] = PORT
-    st.session_state['response_queue'] = queue.Queue()
-    st.session_state['client'] = create_paho_client()
-    setup_paho_client(
-        st.session_state['client'],
-        HIVEMQ_USERNAME,
-        HIVEMQ_PASSWORD,
-        HIVEMQ_HOST,
-        PORT,
-        DEVICE_ID,
-        st.session_state['response_queue']
-    )
-
 st.markdown("## Commands")
 commands = [
     "query/angles", 
@@ -146,7 +120,42 @@ elif st.session_state.selected_command == "control/gripper":
     args = {"gripper_value": gripper_value, "speed": speed}
 
 with st.form("mqtt_form"):
-    if st.form_submit_button("Send Command"):
+    submitted = st.form_submit_button("Send Command")
+    if submitted:
+        # Check if client exists in session_state
+        if st.session_state['client'] is not None:
+            # Check if credentials have changed
+            credentials_changed = (
+                st.session_state.get('HIVEMQ_USERNAME') != HIVEMQ_USERNAME or
+                st.session_state.get('HIVEMQ_PASSWORD') != HIVEMQ_PASSWORD or
+                st.session_state.get('HIVEMQ_HOST') != HIVEMQ_HOST or
+                st.session_state.get('DEVICE_ID') != DEVICE_ID or
+                st.session_state.get('PORT') != PORT
+            )
+            if credentials_changed:
+                # Disconnect old client and create new one
+                st.session_state['client'].disconnect()
+                st.session_state['client'] = None  # Set to None to force reinitialization
+        if st.session_state['client'] is None:
+            # Create new client
+            st.session_state['response_queue'] = queue.Queue()
+            st.session_state['client'] = create_paho_client()
+            setup_paho_client(
+                st.session_state['client'],
+                HIVEMQ_USERNAME,
+                HIVEMQ_PASSWORD,
+                HIVEMQ_HOST,
+                PORT,
+                DEVICE_ID,
+                st.session_state['response_queue']
+            )
+            # Store the credentials in session_state
+            st.session_state['HIVEMQ_USERNAME'] = HIVEMQ_USERNAME
+            st.session_state['HIVEMQ_PASSWORD'] = HIVEMQ_PASSWORD
+            st.session_state['HIVEMQ_HOST'] = HIVEMQ_HOST
+            st.session_state['DEVICE_ID'] = DEVICE_ID
+            st.session_state['PORT'] = PORT
+
         payload = {"command": st.session_state.selected_command, "args": args}
         st.markdown("### Payload")
         st.write(payload)
@@ -166,4 +175,4 @@ with st.form("mqtt_form"):
             else:
                 st.write(response)
         else:
-            st.write("Timed out waiting for response. Is the on-device server running?")
+            st.write("Timed out waiting for response. Is the on-device server running?")