Kibana version:
8.6.0

Elasticsearch version:
8.6.0

Describe the bug:

1. Created a runtime field - the preview shows the correct value
2. The value of the runtime field in Discover is incorrect
3. An aggregation, for example sum on the runtime field in a Lens table produces an incorrect value

Steps to reproduce:

Try to create a runtime field called actual_bytes

def actual_bytes = 0.0;
if (doc['causes.actual'].size() != 0){
    actual_bytes = doc['causes.actual'][0];
}
emit(actual_bytes);

Snippet of document:

    "causes": [
      {
        "probability": 0.01,
        "function": "high_sum",
        "function_description": "sum",
        "typical": [
          377.61130035049564
        ],
        "actual": [
          20000
        ],
        "field_name": "source.bytes",
        "over_field_name": "destination.geo.continent_name",
        "over_field_value": "Europe"
      }

Expected behavior:

Expect that the runtime field works as expected in Lens and Discover.

Screenshots (if relevant):

Runtime preview is correct

Notice that the value of the runtime field in Discover is 0 whereas it should have been 20000 for the document in the screenshot

Notice that an aggregation (sum) on the runtime field produces a null(?) value