Scripted fields disappear

[psaiz]

Plugin version:
6.2.4-3
Kibana version:
6.2.4
Plugins installed:
knql-plugin
Description of the problem including expected versus actual behavior:
The 'scripted fields' created on an index pattern disappear

Steps to reproduce:

1. Go to management, select an index pattern, and create a new 'scripted field'. Any name, leave it as a number, and the script '4', for instance.
2. Go to discover tab.
3. Go back to management -> index patterns. The scripted field should still be there
4. Open a new private window in the browser, and go to management -> index patterns. The scripted field is not there.

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

If using docker, include your docker file: