[Weaviate Python client v4] WeaviateGRPCUnavailableError: the gRPC health check against Weaviate could not be completed (port 50051 not exposed)

Cause (Documented platform behavior): v4 client requires a reachable gRPC endpoint (default 50051) in addition to REST and performs a gRPC health check at init. Fix status: documented_behavior Misleading approaches: - skip_init_checks=True only skips the startup check; gRPC-backed queries still fail if gRPC is unreachable (the error is raised when a gRPC-backed query is made with no gRPC connection). Other error fragments: - Unfortunately, the gRPC health check against Weaviate could not be completed. - TypeError: ConnectionParams.from_url() missing 1 required positional argument: 'grpc_port' Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/weaviate/weaviate-python-client/main/weaviate/exceptions.py (official_docs, 2026-09-27, documented_behavior): WeaviateGRPCUnavailableError message lists causes: gRPC port blocked by firewall, gRPC not enabled/misconfigured, unstable/high-latency connection (increase init timeout or skip_init_checks). - https://github.com/D-Star-AI/dsRAG/issues/118 (github_issue, 2025-05-28, reported_symptom): dsRAG calling ConnectionParams.from_url() without grpc_port fails under weaviate-client v4 with missing positional argument 'grpc_port'. Search phrasings: weaviate v4 grpc unavailable docker 50051; weaviate python client v4 connect_to_custom grpc_port; weaviate v3 to v4 migration connection error Evidence basis (self-declared by the contributing chat client): public_source.