diff --git a/server/__main__.py b/server/__main__.py
index 0ae5d3c7..1948bd4d 100755
--- a/server/__main__.py
+++ b/server/__main__.py
@@ -27,7 +27,7 @@ from logger import mylog
 from helper import filePermissions
 from utils.datetime_utils import timeNowUTC
 from app_state import updateState
-from api import update_api, check_activity
+from api import update_api, check_activity, update_GUI_port
 from scan.session_events import process_scan
 from initialise import importConfigs, renameSettings
 from database import DB
@@ -85,6 +85,9 @@ def main():
     # Initialize the WorkflowManager
     workflow_manager = WorkflowManager(db)
 
+    #Run this once to update the defined GUI port for the activity check
+    update_GUI_port()
+
     # ===============================================================================
     # This is the main loop of NetAlertX
     # ===============================================================================
@@ -261,9 +264,8 @@ def main():
         if userUpdatedDevices:
             update_api(db, all_plugins, True, ["devices"], userUpdatedDevices)
 
-        # loop
         # ------------------------------------------------------------------
-        # Dynamic sleep (energy saving)
+        # Loop with dynamic sleep if enabled (energy saving)
         # ------------------------------------------------------------------
         if conf.DEEP_SLEEP:
             is_active = check_activity()
@@ -281,8 +283,6 @@ def main():
             time.sleep(5)
 
 
-
-
 # ===============================================================================
 # BEGIN
 # ===============================================================================
diff --git a/server/api.py b/server/api.py
index 90b1db49..b65d23e1 100755
--- a/server/api.py
+++ b/server/api.py
@@ -3,6 +3,7 @@ import json
 import time
 import threading
 import datetime
+import os
 
 # Register NetAlertX modules
 import conf
@@ -21,6 +22,7 @@ from const import (
     sql_notifications_all,
     sql_online_history,
     sql_devices_filters,
+    defaultWebPort,
 )
 from db.db_helper import get_sql_devices_tiles
 from logger import mylog
@@ -34,6 +36,8 @@ from api_server.api_server_start import start_server
 
 apiEndpoints = []
 
+hex_gui_port = None
+
 # Lock for thread safety
 api_lock = threading.Lock()
 periodic_write_lock = threading.Lock()
@@ -253,6 +257,21 @@ def stop_periodic_write():
             mylog("trace", ["[API] periodic_write thread stopped."])
 
 
+def update_GUI_port():
+    """
+        Grabs the PORT for the webinterface and converts it to HEX to use for activity checks
+    """
+    global hex_gui_port
+
+    gui_port_string = os.environ.get('PORT', str(defaultWebPort))
+    try:
+        port = int(gui_port_string)
+    except (TypeError, ValueError):
+        mylog("none", [f"[API] Invalid PORT value '{gui_port_string}', falling back to {defaultWebPort}"])
+        port = defaultWebPort
+    hex_gui_port = ':' + format(port, '04X')
+
+
 def check_activity():
     """
     Check for active TCP connections on the host.
@@ -271,10 +290,11 @@ def check_activity():
           (e.g., UI vs other services).
         - Fail-safe: returns False on any read/parse error.
     """
+
     try:
         with open("/proc/net/tcp", "r") as f:
             for line in f:
-                if " 01 " in line:  # ESTABLISHED
+                if hex_gui_port in line and " 01 " in line:
                     return True
     except:
         pass
diff --git a/server/const.py b/server/const.py
index 9762ed69..30e91be5 100755
--- a/server/const.py
+++ b/server/const.py
@@ -30,6 +30,7 @@ logRoot = LOG_PATH_STR
 
 dbFileName = "app.db"
 confFileName = "app.conf"
+defaultWebPort = 20211
 
 confPath = CONFIG_PATH_WITH_TRAILING_SEP + confFileName
 dbPath = DB_PATH_WITH_TRAILING_SEP + dbFileName