Is s3 api call create_multipart_upload not concurrent-safe?

[tommy-bump-be]

I implemented upload by using boto3.
My server enviroment

server = AWS app runner, FastApi
rdbms = Postgresql
orm = sqlalchemy> 2.0 with AsyncSession
nosql = DynamoDB

When I handle just discrete request to make multipart upload, I have no problem.

But when I confront burst request, generated upload_id using boto3 doesn`t work.(When I call list_parts api it returns no such upload)

Did you experince this issue?