ReadyAPI 4.1.0 gRPC client fails with NotSslRecordException against plaintext gRPC server

Environment

ReadyAPI 4.1.0

 Build Date: 2026-06-25

Windows 11

gRPC Server: ReceiverGrpcServer.exe

Endpoint: 127.0.0.1:50051 Proto: receiver_control.proto

Problem

io.grpc.StatusRuntimeException: UNAVAILABLE: io exception Caused by: io.netty.handler.ssl.NotSslRecordException: not an SSL/TLS record

Verified

✅ TLS disabled in ReadyAPI

✅ Connection Settings disabled (grayed out)

✅ grpcurl works:

grpcurl -plaintext ^ -import-path . ^ -proto receiver_control.proto ^ -d "{\"config\":{\"connection_name\":\"Laborum1\",\"tcp\":{\"host\":\"10.0.84.233\",\"port\":3001}}}" ^ 127.0.0.1:50051 receiver_control.ReceiverControlService/UpsertConnectionConfig

Response:

{ "success": true, "message": "Connection config added: Laborum1" }

Question

Why does ReadyAPI 4.1.0 create an SSL handler (NotSslRecordException) even though TLS is disabled and the server is a plaintext gRPC service?