None of the objects returned for allow_registry_cache (Postgres online store, vector_enabled)

## Description

When using the Postgres online store with `vector_enabled`, none of the objects are returned for `allow_registry_cache`. This issue is reproducible and may be due to either:
- The caching mechanism itself being broken
- Retrieval of cached registry items failing

## Steps to Reproduce
1. Use Postgres online store with `vector_enabled`.
2. Attempt to retrieve objects with `allow_registry_cache`.
3. Observe that no objects are returned.

## Expected Behavior
Objects should be returned from the cache if present.

## Actual Behavior
None of the objects are returned.

## Additional Notes
- This could be an issue with the caching logic or the retrieval of cached registry items.
- Needs investigation to determine the root cause.

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Please investigate and provide a fix or further guidance.