diff --git a/test/authoritative_fields/test_ip_format_and_locking.py b/test/authoritative_fields/test_ip_format_and_locking.py
index bb5ccdc1..a4fdb4e3 100644
--- a/test/authoritative_fields/test_ip_format_and_locking.py
+++ b/test/authoritative_fields/test_ip_format_and_locking.py
@@ -80,30 +80,52 @@ def test_invalid_ip_values_rejected(scan_db, mock_ip_handlers):
         assert row["devPrimaryIPv4"] == "192.168.1.50", f"Failed on {invalid_ip}"
 
 
-def test_ipv4_ipv6_mixed_in_multiple_scans(scan_db, mock_ip_handlers):
-    """Multiple scans with different IP types should set both primary fields correctly."""
+def test_ipv4_then_ipv6_scan_updates_primary_ips(scan_db, mock_ip_handlers):
+    """
+    Test that multiple scans with different IP types correctly update:
+    - devLastIP to the latest scan
+    - devPrimaryIPv4 and devPrimaryIPv6 appropriately
+    """
     cur = scan_db.cursor()
+
+    # 1️⃣ Create device
     cur.execute("INSERT INTO Devices (devMac) VALUES (?)", ("AA:BB:CC:DD:EE:04",))
-
-    # Scan 1: IPv4
-    cur.execute("INSERT INTO CurrentScan (scanMac, scanLastIP, scanSourcePlugin, scanLastConnection) VALUES (?, ?, ?, ?)",
-                ("AA:BB:CC:DD:EE:04", "192.168.1.100", "ARPSCAN", "2025-01-01 01:00:00"))
     scan_db.commit()
+
     db = Mock(sql_connection=scan_db, sql=cur)
-    device_handling.update_devices_data_from_scan(db)
-    device_handling.update_ipv4_ipv6(db)
 
-    # Scan 2: IPv6
-    cur.execute("DELETE FROM CurrentScan")
-    cur.execute("INSERT INTO CurrentScan (scanMac, scanLastIP, scanSourcePlugin, scanLastConnection) VALUES (?, ?, ?, ?)",
-                ("AA:BB:CC:DD:EE:04", "fe80::1", "IPv6SCAN", "2025-01-01 02:00:00"))
+    # 2️⃣ First scan: IPv4
+    cur.execute(
+        "INSERT INTO CurrentScan (scanMac, scanLastIP, scanSourcePlugin, scanLastConnection) VALUES (?, ?, ?, ?)",
+        ("AA:BB:CC:DD:EE:04", "192.168.1.100", "ARPSCAN", "2025-01-01 01:00:00")
+    )
     scan_db.commit()
-    device_handling.update_devices_data_from_scan(db)
-    device_handling.update_ipv4_ipv6(db)
 
-    row = cur.execute("SELECT devPrimaryIPv4, devPrimaryIPv6 FROM Devices WHERE devMac = ?", ("AA:BB:CC:DD:EE:04",)).fetchone()
-    assert row["devPrimaryIPv4"] == "192.168.1.100"
-    assert row["devPrimaryIPv6"] == "fe80::1"
+    with patch("server.scan.device_handling.get_plugin_authoritative_settings", return_value={}):
+        device_handling.update_devices_data_from_scan(db)
+        device_handling.update_ipv4_ipv6(db)
+
+    # 3️⃣ Second scan: IPv6
+    cur.execute("DELETE FROM CurrentScan")
+    cur.execute(
+        "INSERT INTO CurrentScan (scanMac, scanLastIP, scanSourcePlugin, scanLastConnection) VALUES (?, ?, ?, ?)",
+        ("AA:BB:CC:DD:EE:04", "fe80::1", "IPv6SCAN", "2025-01-01 02:00:00")
+    )
+    scan_db.commit()
+
+    with patch("server.scan.device_handling.get_plugin_authoritative_settings", return_value={}):
+        device_handling.update_devices_data_from_scan(db)
+        device_handling.update_ipv4_ipv6(db)
+
+    # 4️⃣ Verify results
+    row = cur.execute(
+        "SELECT devLastIP, devPrimaryIPv4, devPrimaryIPv6 FROM Devices WHERE devMac = ?",
+        ("AA:BB:CC:DD:EE:04",)
+    ).fetchone()
+
+    assert row["devLastIP"] == "fe80::1"       # Latest scan IP (IPv6)
+    assert row["devPrimaryIPv4"] == "192.168.1.100"  # IPv4 preserved
+    assert row["devPrimaryIPv6"] == "fe80::1"        # IPv6 set
 
 
 def test_ipv4_address_format_variations(scan_db, mock_ip_handlers):
diff --git a/test/authoritative_fields/test_ip_update_logic.py b/test/authoritative_fields/test_ip_update_logic.py
index 309ed7cc..5b4e3e4c 100644
--- a/test/authoritative_fields/test_ip_update_logic.py
+++ b/test/authoritative_fields/test_ip_update_logic.py
@@ -26,17 +26,22 @@ def mock_device_handling():
         yield
 
 
-def test_primary_ipv6_is_set_and_ipv4_preserved(scan_db, mock_device_handling):
+def test_ipv6_update_preserves_ipv4(scan_db, mock_device_handling):
+    """
+    Test that when a device already has a primary IPv4 and receives an IPv6 scan:
+    - devLastIP is updated to the latest IP (IPv6)
+    - devPrimaryIPv6 is set to the new IPv6
+    - devPrimaryIPv4 is preserved
+    """
     cur = scan_db.cursor()
 
-    # 1. Create device
+    # 1️⃣ Create device with IPv4
     cur.execute(
         "INSERT INTO Devices (devMac, devLastIP, devPrimaryIPv4, devName) VALUES (?, ?, ?, ?)",
         ("AA:BB:CC:DD:EE:FF", "192.168.1.10", "192.168.1.10", "Device")
     )
 
-    # 2. Insert Scan with a SPECIFIC plugin name
-    # This is critical so the logic inside update_devices_data_from_scan finds it
+    # 2️⃣ Insert a scan reporting IPv6
     cur.execute(
         """
         INSERT INTO CurrentScan (scanMac, scanLastIP, scanSourcePlugin, scanLastConnection)
@@ -48,20 +53,20 @@ def test_primary_ipv6_is_set_and_ipv4_preserved(scan_db, mock_device_handling):
 
     db = Mock(sql_connection=scan_db, sql=cur)
 
-    # We must mock get_plugin_authoritative_settings to allow updates from "TEST_PLUGIN"
+    # 3️⃣ Mock plugin authoritative settings
     with patch("server.scan.device_handling.get_plugin_authoritative_settings", return_value={}):
         device_handling.update_devices_data_from_scan(db)
         device_handling.update_ipv4_ipv6(db)
 
+    # 4️⃣ Verify the device fields
     row = cur.execute(
         "SELECT devLastIP, devPrimaryIPv4, devPrimaryIPv6 FROM Devices WHERE devMac = ?",
         ("AA:BB:CC:DD:EE:FF",),
     ).fetchone()
 
-    # These were failing because devLastIP remained 192.168.1.10
-    assert row["devLastIP"] == "2001:db8::1"
-    assert row["devPrimaryIPv6"] == "2001:db8::1"
-    assert row["devPrimaryIPv4"] == "192.168.1.10"
+    assert row["devLastIP"] == "2001:db8::1"        # Latest IP is now IPv6
+    assert row["devPrimaryIPv6"] == "2001:db8::1"   # IPv6 field updated
+    assert row["devPrimaryIPv4"] == "192.168.1.10"  # IPv4 preserved
 
 
 def test_primary_ipv4_is_set_and_ipv6_preserved(scan_db, mock_device_handling):