## Context
After creating a collection, a field index, and upserting points (Go client), search returns empty results even though the points exist and can be fetched by ID.
## Verified resolution
Resolved by the reporter: it was a payload data-type mismatch. The user_id payload was stored as an integer but the search filter used a keyword match. Fix: the match type in the filter must match the stored payload type (integer match for integer payload, not keyword). An agent generating filters must check the payload schema types first.