Marking not working correctly on multiple items

[oliverfoster]

Subject of the issue

should be 2 ticks a cross and a tick

    "_answers": [
        ["alpha", "a"],
        ["beta", "b"],
        ["gamma"],
        ["delta", "d"]
    ],
    "_items": [
      {
        "prefix": "pref1",
        "suffix": "suff1",
        "placeholder": "Enter answer here1"
      },
      {
        "prefix": "pref2",
        "suffix": "suff2",
        "placeholder": "Enter answer here2"
      },
      {
        "prefix": "pref3",
        "suffix": "suff3",
        "placeholder": "Enter answer here3"
      },
      {
        "prefix": "pref4",
        "suffix": "suff4",
        "placeholder": "Enter answer here4"
      }
    ],