diff --git a/desktop_env/providers/aws/config.py b/desktop_env/providers/aws/config.py
index 5c43838..ef24881 100644
--- a/desktop_env/providers/aws/config.py
+++ b/desktop_env/providers/aws/config.py
@@ -3,7 +3,7 @@ import os
 
 # Default TTL minutes for instance auto-termination (cloud-side scheduler)
 # Can be overridden via environment variable DEFAULT_TTL_MINUTES
-DEFAULT_TTL_MINUTES: int = int(os.getenv("DEFAULT_TTL_MINUTES", "60"))
+DEFAULT_TTL_MINUTES: int = int(os.getenv("DEFAULT_TTL_MINUTES", "180"))
 
 # Master switch for TTL feature
 ENABLE_TTL: bool = os.getenv("ENABLE_TTL", "true").lower() == "true"
diff --git a/desktop_env/providers/aws/provider.py b/desktop_env/providers/aws/provider.py
index 124e142..d5ad06e 100644
--- a/desktop_env/providers/aws/provider.py
+++ b/desktop_env/providers/aws/provider.py
@@ -108,13 +108,52 @@ class AWSProvider(Provider):
             # Step 1: Retrieve the original instance details
             instance_details = ec2_client.describe_instances(InstanceIds=[path_to_vm])
             instance = instance_details['Reservations'][0]['Instances'][0]
-            security_groups = [sg['GroupId'] for sg in instance['SecurityGroups']]
-            subnet_id = instance['SubnetId']
-            instance_type = instance['InstanceType']
+            # Resolve security groups with fallbacks
+            security_groups = [sg['GroupId'] for sg in instance.get('SecurityGroups', []) if 'GroupId' in sg]
+            if not security_groups:
+                env_sg = os.getenv('AWS_SECURITY_GROUP_ID')
+                if env_sg:
+                    security_groups = [env_sg]
+                    logger.info("SecurityGroups missing on instance; using AWS_SECURITY_GROUP_ID from env")
+                else:
+                    raise ValueError("No security groups found on instance and AWS_SECURITY_GROUP_ID not set")
+
+            # Resolve subnet with fallbacks
+            subnet_id = instance.get('SubnetId')
+            if not subnet_id:
+                nis = instance.get('NetworkInterfaces', []) or []
+                if nis and isinstance(nis, list):
+                    for ni in nis:
+                        if isinstance(ni, dict) and ni.get('SubnetId'):
+                            subnet_id = ni.get('SubnetId')
+                            break
+                if not subnet_id:
+                    env_subnet = os.getenv('AWS_SUBNET_ID')
+                    if env_subnet:
+                        subnet_id = env_subnet
+                        logger.info("SubnetId missing on instance; using AWS_SUBNET_ID from env")
+                    else:
+                        raise ValueError("SubnetId not available on instance, NetworkInterfaces, or environment")
+
+            # Resolve instance type with fallbacks
+            instance_type = instance.get('InstanceType') or os.getenv('AWS_INSTANCE_TYPE') or 't3.large'
+            if instance.get('InstanceType') is None:
+                logger.info(f"InstanceType missing on instance; using '{instance_type}' from env/default")
             
-            # Step 2: Terminate the old instance
-            ec2_client.terminate_instances(InstanceIds=[path_to_vm])
-            logger.info(f"Old instance {path_to_vm} has been terminated.")
+            # Step 2: Terminate the old instance (skip if already terminated/shutting-down)
+            state = (instance.get('State') or {}).get('Name')
+            if state in ['shutting-down', 'terminated']:
+                logger.info(f"Old instance {path_to_vm} is already in state '{state}', skipping termination.")
+            else:
+                try:
+                    ec2_client.terminate_instances(InstanceIds=[path_to_vm])
+                    logger.info(f"Old instance {path_to_vm} has been terminated.")
+                except ClientError as e:
+                    error_code = getattr(getattr(e, 'response', {}), 'get', lambda *_: None)('Error', {}).get('Code') if hasattr(e, 'response') else None
+                    if error_code in ['InvalidInstanceID.NotFound', 'IncorrectInstanceState']:
+                        logger.info(f"Ignore termination error for {path_to_vm}: {error_code}")
+                    else:
+                        raise
 
             # Step 3: Launch a new instance from the snapshot(AMI) with performance optimization
             logger.info(f"Launching a new instance from AMI {snapshot_name}...")
diff --git a/run_maestro.py b/run_maestro.py
index 5366ad8..b411112 100644
--- a/run_maestro.py
+++ b/run_maestro.py
@@ -544,7 +544,7 @@ def get_unfinished(
 
 if __name__ == "__main__":
     """
-    xvfb-run -a python run_maestro.py --test_all_meta_path evaluation_examples/test_nogdrive.json --num_envs 15
+    xvfb-run -a python run_maestro.py --test_all_meta_path evaluation_examples/test_nogdrive.json --num_envs 1 --headless --result_dir ./results_maestro_debug
     """
 
     os.environ["TOKENIZERS_PARALLELISM"] = "false"