diff --git a/scripts/provision_fabric.py b/scripts/provision_fabric.py
index cef22d0..8662ede 100644
--- a/scripts/provision_fabric.py
+++ b/scripts/provision_fabric.py
@@ -399,11 +399,12 @@ PREFIXES = [
 
 def get_or_create(endpoint, search_params: dict, create_params: dict) -> Any:
     """Get existing object or create new one."""
-    obj = endpoint.get(**search_params)
-    if obj:
-        return obj, False
+    # Use filter() instead of get() to handle multiple results gracefully
+    results = list(endpoint.filter(**search_params))
+    if results:
+        return results[0], False
 
-    obj = endpoint.create({**search_params, **create_params})
+    obj = endpoint.create(create_params)
     return obj, True
 
 
@@ -501,6 +502,10 @@ def create_vlans(nb: pynetbox.api, site) -> dict:
     result = {}
 
     # VLAN Group
+    # For NetBox 4.x, scope_type/scope_id are deprecated in favor of scope_object
+    # but for simple site scope we can just pass scope_type and scope_id or
+    # rely on backward compatibility if it exists. Ideally we check NetBox version
+    # but here we'll try to be compatible.
     vlan_group, created = get_or_create(
         nb.ipam.vlan_groups,
         {"slug": VLAN_GROUP_NAME},
@@ -515,7 +520,11 @@ def create_vlans(nb: pynetbox.api, site) -> dict:
         vlan_obj, created = get_or_create(
             nb.ipam.vlans,
             {"vid": vlan["vid"], "group_id": vlan_group.id},
-            {"name": vlan["name"], "description": vlan.get("description", "")},
+            {
+                "name": vlan["name"],
+                "description": vlan.get("description", ""),
+                "group": vlan_group.id,  # Create expects 'group', filter expects 'group_id'
+            },
         )
         log_result("VLAN", "VLAN", f"{vlan['vid']} ({vlan['name']})", created)
         result["vlans"][vlan["vid"]] = vlan_obj
@@ -578,10 +587,14 @@ def create_prefixes(nb: pynetbox.api, vrfs: dict):
             if vrf_id:
                 vrf_id = vrf_id.id
 
+        create_params = {"prefix": prefix_def["prefix"], "description": prefix_def.get("description", "")}
+        if vrf_id:
+            create_params["vrf"] = vrf_id
+
         prefix, created = get_or_create(
             nb.ipam.prefixes,
             {"prefix": prefix_def["prefix"], "vrf_id": vrf_id},
-            {"description": prefix_def.get("description", "")},
+            create_params,
         )
         log_result("Prefix", "Prefix", prefix_def["prefix"], created)
 
@@ -736,8 +749,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
 
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": spine["loopback0"]},
             {
+                "address": spine["loopback0"],
+                "assigned_object_id": intf.id,
+            },
+            {
+                "address": spine["loopback0"],
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": intf.id,
                 "description": f"{spine['name']} Router-ID",
@@ -753,8 +770,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
         intf = interfaces[leaf["name"]]["Loopback0"]
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": leaf["loopback0"]},
             {
+                "address": leaf["loopback0"],
+                "assigned_object_id": intf.id,
+            },
+            {
+                "address": leaf["loopback0"],
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": intf.id,
                 "description": f"{leaf['name']} Router-ID",
@@ -766,8 +787,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
         intf = interfaces[leaf["name"]]["Loopback1"]
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": leaf["loopback1"]},
             {
+                "address": leaf["loopback1"],
+                "assigned_object_id": intf.id,
+            },
+            {
+                "address": leaf["loopback1"],
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": intf.id,
                 "description": f"{leaf['name']} VTEP",
@@ -781,8 +806,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
         spine_intf = interfaces["spine1"][f"Ethernet{list(SPINE1_P2P.keys()).index(leaf_name) + 1}"]
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": spine_ip},
             {
+                "address": spine_ip,
+                "assigned_object_id": spine_intf.id,
+            },
+            {
+                "address": spine_ip,
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": spine_intf.id,
                 "description": f"spine1 to {leaf_name}",
@@ -794,8 +823,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
         leaf_intf = interfaces[leaf_name]["Ethernet11"]
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": leaf_ip},
             {
+                "address": leaf_ip,
+                "assigned_object_id": leaf_intf.id,
+            },
+            {
+                "address": leaf_ip,
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": leaf_intf.id,
                 "description": f"{leaf_name} to spine1",
@@ -808,8 +841,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
         spine_intf = interfaces["spine2"][f"Ethernet{list(SPINE2_P2P.keys()).index(leaf_name) + 1}"]
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": spine_ip},
             {
+                "address": spine_ip,
+                "assigned_object_id": spine_intf.id,
+            },
+            {
+                "address": spine_ip,
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": spine_intf.id,
                 "description": f"spine2 to {leaf_name}",
@@ -820,8 +857,12 @@ def create_ip_addresses(nb: pynetbox.api, devices: dict, interfaces: dict, vrfs:
         leaf_intf = interfaces[leaf_name]["Ethernet12"]
         ip, created = get_or_create(
             nb.ipam.ip_addresses,
-            {"address": leaf_ip},
             {
+                "address": leaf_ip,
+                "assigned_object_id": leaf_intf.id,
+            },
+            {
+                "address": leaf_ip,
                 "assigned_object_type": "dcim.interface",
                 "assigned_object_id": leaf_intf.id,
                 "description": f"{leaf_name} to spine2",