Error like 'Zilliz Cloud partition key routing error' or similar (e.g., load/search fails with OOM, timeout, or routing failure) when performing searches/queries on partition key-enabled collections without partition key filter in expr.

Collections with partition keys require explicit filtering on the partition key field in search/query requests to route to correct partitions; omitting the filter causes full collection scan instead of optimized partition routing, leading to errors like timeouts, OOM, or 'routing failed' during partition resolution.