D3js force node xy start position

I have a node with fx / fy parameter when running a simulation. This node is fixed in the correct position. But now I want to determine the x and y coordinates for one or more other nodes (in this example: number 10 in the jsfiddle), the goal is to start the simulation of these "uncommitted" nodes at a given position, not 0/0. Why is node fixed at 0/0?

Jsfiddle example: https://jsfiddle.net/6g9howo7/2/

                var nodes = [
                {
                    "id" : "1",
                    "fx" : "225",
                    "fy" : "225"
                },
                {
                    "id" : "2"
                },
                {
                    "id" : "3"
                },
                {
                    "id" : "4"
                },
                {
                    "id" : "5"
                },
                {
                    "id" : "6"
                },
                {
                    "id" : "7"
                },
                {
                    "id" : "8"
                },
                {
                    "id" : "9"
                },
                {
                    "id" : "10",
                    "x" : "125",
                    "y" : "125" 
                },
                {
                    "id" : "11"
                },
                {
                    "id" : "12"
                },
                {
                    "id" : "13"
                },
                {
                    "id" : "14"
                },
                {
                    "id" : "15"
                }
            ]

            var links = 
            [
                {
                    "source" : 1,
                    "target" : 2
                },
                {
                    "source" : 1,
                    "target" : 3
                },
                {
                    "source" : 1,
                    "target" : 4
                },
                {
                    "source" : 1,
                    "target" : 5
                },
                {
                    "source" : 1,
                    "target" : 6
                },
                {
                    "source" : 1,
                    "target" : 7
                },
                {
                    "source" : 1,
                    "target" : 8
                },
                {
                    "source" : 1,
                    "target" : 9
                },
                {
                    "source" : 1,
                    "target" : 10
                },
                {
                    "source" : 10,
                    "target" : 11
                },
                {
                    "source" : 10,
                    "target" : 12
                },
                {
                    "source" : 10,
                    "target" : 13
                },
                {
                    "source" : 10,
                    "target" : 14
                },
                {
                    "source" : 10,
                    "target" : 15
                }
            ]


            var svg = d3.select("svg")

                var zoom = d3.zoom()
                    .on("zoom", zoomed);
                    //.scaleExtent([1 / 8, 4])

                    svg
                        .call(zoom).on("dblclick.zoom", null)


            var g = svg.append("g");

            function zoomed() {
            g.attr("transform", d3.event.transform);
            }

            var color = d3.scaleOrdinal(d3.schemeCategory20);



            var simulation = d3.forceSimulation()
                //.force("link", d3.forceLink().id(function(d) { return d.id; }).distance(function(d) {return d.distance/2;}).strength(1))
            .force("link", d3.forceLink().id(function(d) { return d.id; }).distance(10).strength(1))
            .force("charge", d3.forceManyBody().strength(-10).distanceMax(100));
            //.force("center", d3.forceCenter(1000, 1000));
            //.force("y", d3.forceY(500))
            //.force("x", d3.forceX(500));
            //.force("collide",d3.forceCollide(.5));
            //.force("collide",d3.forceCollide( function(d){return d.r + 8 }).iterations(4) );


            var link = g.append("g")
                .attr("class", "links")
                .selectAll("line")
                .data(links)
                .enter().append("line")
                    .attr("stroke-width", 1 /*function(d) { return Math.sqrt(2); }*/)
                .style("stroke", 'red');

            var node = g.append("g")
                .attr("class", "nodes")
                .selectAll("circle")
                .data(nodes)
                .enter().append("circle")
            .attr("r",3)
            //  .attr("cx", function(d) { return d.x; })
            //  .attr("cy", function(d) { return d.y; })
                .on("dblclick", dblclick)
                .call(d3.drag()
                    .on("start", dragstarted)
                    .on("drag", dragged)
                    .on("end", dragended));


                node.append("title")
                    .text(function(d) { return d.id; });


            simulation.nodes(nodes)
                //  .alphaDecay(0.5)
                .velocityDecay(0.1)
                .on("tick", ticked);

            simulation.force("link")
                .links(links);


            function ticked() {
            link
                .attr("x1", function(d) { return d.source.x; })
                .attr("y1", function(d) { return d.source.y; })
                .attr("x2", function(d) { return d.target.x; })
                .attr("y2", function(d) { return d.target.y; });

            node
                .attr("cx", function(d) { return d.x; })
                .attr("cy", function(d) { return d.y; });

            }

            function dblclick(d) {
            d.fx = null;
            d.fy = null;
            }

            function dragstarted(d) {
            //if (!d3.event.active) simulation.alphaTarget(0.3).restart();
            simulation.restart();
            // simulation.alpha -> redémarre la période de simulation
            simulation.alpha(1.0);
            d.fx = d.x;
            d.fy = d.y;
            }

            //Grid
            var grid = 50;

            function dragged(d,i) {
            //force.stop();
            //var grid = 50;

            var gx = Math.round(d3.event.x/grid)*grid;
            var gy = Math.round(d3.event.y/grid)*grid;

            d.fx = gx;
            d.fy = gy;
            }


            function dragended(d) {
            if (!d3.event.active) simulation.alphaTarget(0);
            //    console.log(d);
            //  d.fx = null;
            //  d.fy = null;
            //  d.fixed = true;
            }

            //Grid
            var width = 7000;
            var height = 7000;


                var lineGraph = g.append("g")
                    .attr("width", width)
                    .attr("height", height);

            // Using for loop to draw multiple horizontal lines
            for (var j=grid; j <= width-grid; j=j+grid) {
                lineGraph.append("svg:line")
                    .attr("x1", grid)
                    .attr("y1", j)
                    .attr("x2", width-grid)
                    .attr("y2", j)
                    .style("stroke", "rgb(119,119,119)")
                    .style("stroke-width", 1);
            };

            // Using for loop to draw multiple vertical lines
            for (var j=grid; j <= height-grid; j=j+grid) {
                lineGraph.append("svg:line")
                    .attr("x1", j)
                    .attr("y1", grid)
                    .attr("x2", j)
                    .attr("y2", height-grid)
                    .style("stroke", "rgb(119,119,119)")
                    .style("stroke-width", 1);
            };