Wrong street name inside an instruction

Hi there,
I’m using Graphhopper offline in an Android Device. When I calculate a route some instructions have no street name and my list of instructions looks like this:

1- Continue on service
2- Turn left on residential
3- Turn right on residential

I’m using this snippet of code to make a Graphhopper request:

        GHRequest req = new GHRequest().setAlgorithm(Parameters.Algorithms.DIJKSTRA_BI);
        req.addPoint(some points);
        List<Double> head = new ArrayList<>();
        req.getHints().put("ch.disable", "true");
        req.getHints().put("instructions", "true");
       GHResponse resp = hopper.route(req);
       InstructionList  list = resp.getBest().getInstructions();

Some suggesgtions about this problem?

What exactly is the problem here? Do you want to include the road_class in the instruction when there is no street name?