Kibana Filter Editor Inconsistent Behavior

[mickymots]

Kibana version: 7.3.1

Elasticsearch version: 7.3.1

Server OS version: Ubuntu 18.04

Browser version: Firefox 70

Browser OS version: Ubuntu 18.04

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

Describe the bug:

Kibana Filter Editor Dialogue Box has inconsistent behavior for Operators. When Operator value = is then "value" drop-down box gets all the keywords from Elasticsearch as you type in "Value"

When Operator value = is one of
then "value" drop-down box only shows 10 sorted value and does not query elastic to get matching keywords

Steps to reproduce:

1. Open Discover Tab
2. click on "Add Filter" Link
3. Select a keyword field in field
4. Select Operator : is
5. In Value field: type a keyword that exists in Elastic but not being shown in drop down right now
6. Value field shows the drop-down's new value from ES
7. now change the operator to : is one of
8. In Value field: type a keyword that exists in Elastic but not being shown in drop down right now
9. Value field remains empty and does not show the drop-down's new value from ES

Expected behavior: Value field should query and show the keywords from ES.

Screenshots (if relevant):

Errors in browser console (if relevant): none

Provide logs and/or server output (if relevant): none

Any additional context: none

[elasticmachine]

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

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)

[lizozom]

Issue exists in master