Autocomplete breaks for all children of bool->filter

[senorsunday]

Kibana version: 7.4.1

Elasticsearch version: 7.4.1

Server OS version: Ubuntu 18

Browser version: Firefox 71

Browser OS version: Windows

Original install method (e.g. download page, yum, from source, etc.): docker

Describe the bug:
Typing an a word (quoted or otherwise) for part of a query does not bring up the autocomplete dropdown for any children of "bool":{"filter", nor does CTRL/CMD+Space.

Steps to reproduce:

1. Create a query using "must" seeing autocomplete working
2. Change "must" to "filter" and see it stop working

GET telemetry/_search
{
  "query": {
    "bool": {
      "filter": [
        {ter}
      ]
    }
  }
}

Expected behavior:
Autocomplete for inside "must" & "filter" queries should be identical

Screenshots (if relevant):

Errors in browser console (if relevant): No errors

Provide logs and/or server output (if relevant): No errors

Any additional context:

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[senorsunday]

I've since found that autocomplete works when you pass key/value pairs directly instead of a list.

GET telemetry/_search
{
  "query": {
    "bool": {
      "filter": {ter} // autocomplete works here
    }
  }
}

But in that case, must, must_not and should all break autocomplete...

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)