diff --git a/app/pipeline/file_manager.py b/app/pipeline/file_manager.py
index b3d6b14..fb62ef6 100644
--- a/app/pipeline/file_manager.py
+++ b/app/pipeline/file_manager.py
@@ -5,6 +5,7 @@ from dataclasses import dataclass
 from datetime import datetime
 from pathlib import Path
 from urllib.parse import urlparse
+from uuid import uuid4
 
 from .config import (
     build_date_parts,
@@ -199,7 +200,7 @@ def check_network_dir_access(
 def check_dir_write_access(
     target_dir: str, samba_conn, source_name: str
 ) -> tuple[bool, str | None]:
-    probe_prefix = f".sfm_write_probe_{int(datetime.now().timestamp() * 1000)}"
+    probe_prefix = f".sfm_write_probe_{uuid4().hex}"
     probe_src = join_path(target_dir, f"{probe_prefix}.tmp")
     probe_dst = join_path(target_dir, f"{probe_prefix}_renamed.tmp")