Category axis skips values

HTML

<script src="http://chartjs.org/dist/master/Chart.bundle.min.js"></script>
<canvas id="canvas" width="400" height="200"></canvas>

JavaScript

var canvas = document.getElementById('canvas');

var config1 = {
  "type": "bar",
  "data": {
    "datasets": [{
      "type": "bar",
      "label": "Bezug",
      "backgroundColor": "#757575",
      "borderColor": "#757575",
      "yAxisID": "axis2",
      "xAxisID": "axis-bar",
      "borderWidth": 2,
      "fill": false,
      "pointRadius": 0,
      "data": [2487, 2745, 4979, 2383, 2389, 2655, 2689, 2656, 2552, 2768, 2882, 2698, 3033, 3075, 3817, 3661, 4780, 3739, 4433, 4738, 4187, 3119, 3543, 2659, 3996, 2833, 2765, 4422, 2843, 1820, 2514, 3010, 2572, 3363, 4732, 2701, 4278, 4352, 3072, 2242, 2722, 5227, 2974, 3945, 5137, 2568, 3931, 3032, 3502, 3874, 3789, 4872, 3211, 2805, 3116, 5166, 4320, 3260, 6280, 3110, 4360, 1770]
    }]
  },
  "options": {
    "responsive": true,
    "maintainAspectRatio": false,
    "hover": {
      "mode": "nearest"
    },
    "scales": {
      "xAxes": [{
        "type": "category",
        "id": "axis-bar",
        "display": true,
        "labels": ["6. Jun", "7. Jun", "8. Jun", "9. Jun", "10. Jun", "11. Jun", "12. Jun", "13. Jun", "14. Jun", "15. Jun", "16. Jun", "17. Jun", "18. Jun", "19. Jun", "20. Jun", "21. Jun", "22. Jun", "23. Jun", "24. Jun", "25. Jun", "26. Jun", "27. Jun", "28. Jun", "29. Jun", "30. Jun", "1. Jul", "2. Jul", "3. Jul", "4. Jul", "5. Jul", "6. Jul", "7. Jul", "8. Jul", "9. Jul", "10. Jul", "11. Jul", "12. Jul", "13. Jul", "14. Jul", "15. Jul", "16. Jul", "17. Jul", "18. Jul", "19. Jul", "20. Jul", "21. Jul", "22. Jul", "23. Jul", "24. Jul", "25. Jul", "26. Jul", "27. Jul", "28. Jul", "29. Jul", "30. Jul", "31. Jul", "1. Aug", "2. Aug", "3. Aug", "4. Aug", "5. Aug", "6. Aug", "7. Aug", "8. Aug"],
        "gridLines": {
          "offsetGridLines": true
        },
        "autoSkip": false
      }, {
        "type": "time",
        "id": "axis-time",
        "display": true,
        "gridLines": {
          "display": false
        },
        "time": {
          "displayFormats": {
            "second":...