diff --git a/lib/couchdb/manager.py b/lib/couchdb/manager.py
index 1086b80..f06a15c 100644
--- a/lib/couchdb/manager.py
+++ b/lib/couchdb/manager.py
@@ -161,7 +161,13 @@ async def get_changes(
             try:
                 doc = self.db.get(change["id"])
                 last_processed_seq = change["seq"]
-                Ygg.save_last_processed_seq(last_processed_seq)
+                if last_processed_seq is not None:
+                    Ygg.save_last_processed_seq(last_processed_seq)
+                else:
+                    logging.warning(
+                        "Received `None` for last_processed_seq. Skipping save."
+                    )
+
                 yield doc
             except Exception as e:
                 logging.warning(f"Error processing change: {e}")
diff --git a/lib/module_utils/sjob_manager.py b/lib/module_utils/sjob_manager.py
index 956bb81..de4cb23 100644
--- a/lib/module_utils/sjob_manager.py
+++ b/lib/module_utils/sjob_manager.py
@@ -1,7 +1,8 @@
 import asyncio
 import re
 import subprocess
-from typing import Any, Optional
+from pathlib import Path
+from typing import Any, Optional, Union
 
 from lib.core_utils.config_loader import configs
 from lib.core_utils.logging_utils import custom_logger
@@ -143,16 +144,21 @@ def __init__(
         )
         self.command_timeout: float = command_timeout
 
-    async def submit_job(self, script_path: str) -> Optional[str]:
+    async def submit_job(self, script_path: Union[str, Path]) -> Optional[str]:
         """Submit a Slurm job using the specified script.
 
         Args:
-            script_path (str): Path to the Slurm script.
+            script_path (Union[str, Path]): Path to the Slurm script.
 
         Returns:
             Optional[str]: The job ID if submission is successful, None otherwise.
         """
-        sbatch_command = ["sbatch", script_path]
+        sbatch_command = ["sbatch", str(script_path)]
+
+        if not Path(script_path).is_file():
+            logging.error(f"Script file does not exist: {script_path}")
+            return None
+
         try:
             process = await asyncio.create_subprocess_exec(
                 *sbatch_command,