diff --git a/gen3workflow/aws/bucket.py b/gen3workflow/aws/bucket.py
index 9d60e0c..8d7bc9c 100644
--- a/gen3workflow/aws/bucket.py
+++ b/gen3workflow/aws/bucket.py
@@ -421,8 +421,10 @@ async def create_user_bucket(user_id: str) -> Tuple[str, str, str]:
     Wrapper for `_create_user_bucket` that handles caching and retries.
 
     Gracefully handles race conditions, for example:
-    `An error occurred (OperationAborted) when calling the PutBucketEncryption operation:
-    A conflicting conditional operation is currently in progress against this resource.`
+    - `An error occurred (OperationAborted) when calling the PutBucketEncryption operation:
+      A conflicting conditional operation is currently in progress against this resource.`
+    - `An error occurred (AlreadyExistsException) when calling the CreateAlias operation:
+      An alias with the name XYZ already exists`
     """
     if USER_BUCKET_CACHE.has(user_id):
         return USER_BUCKET_CACHE.get(user_id)
@@ -437,7 +439,8 @@ async def create_user_bucket(user_id: str) -> Tuple[str, str, str]:
             return bucket_info
         except ClientError as e:
             if (
-                e.response["Error"]["Code"] != "OperationAborted"
+                e.response["Error"]["Code"]
+                not in ["OperationAborted", "AlreadyExistsException"]
                 or attempt == max_tries
             ):
                 raise
diff --git a/gen3workflow/aws/s3_files.py b/gen3workflow/aws/s3_files.py
index 271f300..35739a3 100644
--- a/gen3workflow/aws/s3_files.py
+++ b/gen3workflow/aws/s3_files.py
@@ -139,8 +139,8 @@ def _create_s3_files_system(bucket_name: str, role_arn: str) -> str:
             roleArn=role_arn,
             tags=[
                 {
-                    "Key": "Name",
-                    "Value": get_safe_name_from_hostname(user_id=None),
+                    "key": "Name",
+                    "value": get_safe_name_from_hostname(user_id=None),
                 }
             ],
         )
diff --git a/tests/test_s3_files.py b/tests/test_s3_files.py
index 6cc952e..e4d8aa0 100644
--- a/tests/test_s3_files.py
+++ b/tests/test_s3_files.py
@@ -226,7 +226,7 @@ def test_create_s3_files_system_success(mock_aws_services):
         bucket="arn:aws:s3:::test-bucket",
         prefix="funnel-temp-files/",
         roleArn="arn:aws:iam::123456789012:role/s3files-role",
-        tags=[{"Key": "Name", "Value": "gen3wf-localhost"}],
+        tags=[{"key": "Name", "value": "gen3wf-localhost"}],
     )