Compaction of IRIs with "@list" @container for sets of @list

Compacting this document:

{
  "http://schema.org/prop": [
    {
      "@list": ["foo", "bar"]
    },
    {
      "@list": ["baz", "qux"]
    }
  ]
}

with this context:

{
  "prop": {
    "@id": "http://schema.org/prop",
    "@container": "@list"
  }
}

produces this new document:

{
  "@context": {
    "prop": {
      "@id": "http://schema.org/prop",
      "@container": "@list"
    }
  },
  "prop": [
    "baz",
    "qux"
  ]
}

which is missing the first of the two lists.

(Tested with the JSON-LD playground , PyLD, and the ruby-ld gem)

As far as I can tell, this is caused by step 12.8.7.3 of the compaction algorithm, which sets 'item active property' first to ["foo", "bar"] then to ["baz", "qux"] causing the first value to be overwritten, and lost from the compacted document.

Is this an expected consequence of the algorithm specification?

The issue names step 12.8.7.3 of the JSON-LD 1.1 compaction algorithm but no repository files or tests. Start by reproducing the two-list example in the JSON-LD playground, PyLD, and the ruby-ld gem, then compare the algorithm's handling of repeated @list values. Done means the specification's expected behavior and any required conformance coverage are clearly established.