excludeTags in facets does not exclude a term

Question

My document collection has an attribute cfname2. Using JSON API I can query *:* and facet on this attribute and exclude 00 term:

GET http://localhost:5555/solr/db/query HTTP/1.1
content-type: application/json

{ 
    "query" : "*:*",
    "limit": 0,
    "facet": {
        "t" : {
            "type":  "terms",
            "field": "cfname2",
            "limit": 10,
            "sort":  "index",
            "domain": {"excludeTags": "00"}
        }
    }
}

independent whether I use excludeTags or not, 00 is in the answer:

 "response": {
    "numFound": 20560849,
    "start": 0,
    "numFoundExact": true,
    "docs": []
  },
  "facets": {
    "count": 20560849,
    "t": {
      "buckets": [
        {
          "val": "0",
          "count": 831411
        },
        {
          "val": "00",
          "count": 861685
        },
        {
          "val": "01",
          "count": 198584
        },

I wonder why this does not work. How can I exclude terms matching regex [0-9][0-9] using the above JSON?