diff --git a/front/js/network-tabs.js b/front/js/network-tabs.js
index 708af683..c7e6db02 100644
--- a/front/js/network-tabs.js
+++ b/front/js/network-tabs.js
@@ -13,7 +13,7 @@ function renderNetworkTabs(nodes) {
                       (node.devAlertDown == 1 ? "text-red" : "text-gray50"));
 
     const portLabel = node.node_ports_count ? ` (${node.node_ports_count})` : '';
-    const icon = atob(node.devIcon);
+    const icon = safeAtob(node.devIcon);
     const id = node.devMac.replace(/:/g, '_');
 
     html += `
diff --git a/front/js/ui_components.js b/front/js/ui_components.js
index 34c2cb3e..4fcf96fe 100755
--- a/front/js/ui_components.js
+++ b/front/js/ui_components.js
@@ -971,6 +971,9 @@ function renderDeviceLink(data, container, useName = false) {
   // Build and return badge parts
   const badge = badgeFromDevice(device);
 
+  // Decode once (with a safe fallback) and reuse for both the chip and hover preview
+  const decodedIcon = safeAtob(device.devIcon);
+
   // badge class and hover-info class to container
   $(container)
     .addClass(`${badge.cssClass} hover-node-info`)
@@ -990,13 +993,13 @@ function renderDeviceLink(data, container, useName = false) {
       'data-sleeping': device.devIsSleeping || 0,
       'data-archived': device.devIsArchived || 0,
       'data-isnew':    device.devIsNew      || 0,
-      'data-icon': device.devIcon
+      'data-icon': decodedIcon
     });
 
   return `
     <a href="${badge.url}" target="_blank">
       <span class="custom-chip">
-        <span class="iconPreview">${device.devIcon ? atob(device.devIcon) : ''}</span>
+        <span class="iconPreview">${decodedIcon}</span>
         ${useName ? encodeSpecialChars(device.devName) : data.text}
         <span>
           (${badge.iconHtml})
@@ -1006,6 +1009,17 @@ function renderDeviceLink(data, container, useName = false) {
   `;
 }
 
+// ------------------------------------------
+// Base64-decode a devIcon value, tolerating missing/empty/malformed input
+function safeAtob(value) {
+  if (!value) return '';
+  try {
+    return atob(value);
+  } catch (e) {
+    return '';
+  }
+}
+
 // ------------------------------------------
 // Display device info on hover (attach only once)
 function initHoverNodeInfo() {
@@ -1063,7 +1077,7 @@ function initHoverNodeInfo() {
 
       const html = `
         <div>
-          <b> <div class="iconPreview">${atob(icon)}</div> </b><b class="devName"> ${encodeSpecialChars(name)}</b><br>
+          <b> <div class="iconPreview">${icon || ''}</div> </b><b class="devName"> ${encodeSpecialChars(name)}</b><br>
         </div>
         <hr/>
         <div class="line">
diff --git a/server/database.py b/server/database.py
index bffdde9a..4e63ad43 100755
--- a/server/database.py
+++ b/server/database.py
@@ -228,7 +228,6 @@ class DB:
             ensure_mac_lowercase_triggers(self.sql)
 
             # Prevent/repair dangling devParentMAC references left by deleted devices
-            ensure_dangling_parentmac_cleanup_trigger(self.sql)
             cleanup_existing_dangling_parentmac(self.sql)
 
             # Device history table + audit triggers
@@ -246,9 +245,10 @@ class DB:
         AppEvent_obj(self)
 
         # AppEvent_obj.drop_all_triggers() wipes every trigger in the DB
-        # (including trg_devhist_*) as part of its clean-start routine.
-        # Re-create the device history audit triggers here so they survive.
+        # (including trg_devhist_* and trg_clear_dangling_parentmac_on_delete)
+        # as part of its clean-start routine. Re-create them here so they survive.
         ensure_deviceshistory_triggers(self.sql)
+        ensure_dangling_parentmac_cleanup_trigger(self.sql)
         self.commitDB()
 
     def get_table_as_json(self, sqlQuery, parameters=None):
diff --git a/server/scan/device_handling.py b/server/scan/device_handling.py
index a604e28b..59e5149c 100755
--- a/server/scan/device_handling.py
+++ b/server/scan/device_handling.py
@@ -10,6 +10,7 @@ from models.device_instance import DeviceInstance
 from scan.name_resolution import NameResolver
 from scan.device_heuristics import guess_icon, guess_type
 from db.db_helper import sanitize_SQL_input, list_to_where, safe_int
+from db.db_upgrade import PARENT_MAC_SENTINELS
 from db.authoritative_handler import (
     get_overwrite_sql_clause,
     can_overwrite_field,
@@ -734,7 +735,7 @@ def create_new_devices(db):
     # to a MAC that no longer exists (e.g. that device was since deleted) -
     # falling back to unset rather than seeding new devices with a dangling reference.
     default_parent_mac_setting = get_setting_value("NEWDEV_devParentMAC")
-    if default_parent_mac_setting:
+    if default_parent_mac_setting and default_parent_mac_setting.lower() not in PARENT_MAC_SENTINELS:
         existing_device_macs = {
             str(row[0]).lower() for row in sql.execute("SELECT devMac FROM Devices").fetchall() if row[0]
         }