Server-side streaming which returns bytes not working

[PatSos95]

I have a problem with using the server-side streaming service on Evans. This is the error I get:
> call SomeService
command call: json: cannot unmarshal string into Go value of type map[string]interface {}

This is proto definition of service:
rpc SomeService(google.protobuf.Empty) returns (stream google.protobuf.BytesValue);

I've checked it with the service that returns a stream of integers and it was fine, so I think the problem lies with the return value.

[PatSos95]

I've checked the same service with grpcurl and it worked