Optimade API is not working with v1.1.1

Not sure if it is in the mapping of metainfo to _nmd properties or something in the data. Most searches (e.g. https://nomad-lab.eu/prod/v1/optimade/structures?filter=elements%20HAS%20ALL%20%22Ti%22%2C%20%22O%22%20AND%20nelements%20%3D%202) return something like:

{
  "meta": {
    "query": {
      "representation": "/prod/v1/optimade/structures?filter=elements%20HAS%20ALL%20%22Ti%22%2C%20%22O%22%20AND%20nelements%20%3D%202&response_format=json&page_limit=20&page_offset=0&page_number=0&page_cursor=0&page_above=0&page_below=0&include=references"
    },
    "api_version": "1.0.1",
    "more_data_available": false,
    "time_stamp": "2022-05-18T11:33:56Z",
    "data_returned": 0,
    "provider": {
      "name": "novel materials discovery (NOMAD)",
      "description": "A FAIR data sharing platform for materials science data",
      "prefix": "nmd",
      "homepage": "https://nomad-lab.eu"
    },
    "data_available": 0,
    "implementation": {
      "name": "NOMAD's Optimade implementation",
      "version": "0.14.0",
      "source_url": "https://gitlab.mpcdf.mpg.de/nomad-lab/nomad-FAIR",
      "maintainer": {
        "email": "markus.scheidgen@physik.hu-berlin.de"
      }
    }
  },
  "errors": [
    {
      "status": "500",
      "code": "type_error.integer",
      "title": "ValidationError",
      "detail": "value is not a valid integer",
      "source": {
        "pointer": "/attributes/_nmd_results_properties_electronic_dos_electronic_band_gap_index"
      }
    }
  ]
}