Hi @kuanlu3 ! Welcome to our community 
I believe this is a limit in which Weaviate will stop querying thru the index.
here is where this is raised in code:
So when performing searches or deletions, there are upper limits set to prevent excessive memory usage and long-running requests, which could lead to out-of-memory errors or other performance issues. For example, when deleting objects with a batch delete operation, Weaviate imposes a default limit of 10,000 objects that can be deleted in a single query to protect against unexpected memory surges.
You can still save vectors and objects, however, there is the default limit of 10000 objects to be returned. This value is set by the environment variable QUERY_MAXIMUM_RESULTS as listed here:
Let me know if that helps 