[Ingest Management]: Error 'Agent not found' is displayed for fraction of time on clicking Host under Fleet tab

Kibana version:
Kibana: 7.10.0-SNAPSHOT

Elasticsearch version:
Elasticsearch: 7.10.0-SNAPSHOT

Host OS and Browser version:
Windows 10 , All

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

Description
Error 'Agent not found' is displayed for fraction of time on clicking Host under Fleet tab

Preconditions

1. 7.10.0-SNAPSHOT Kibana cloud environment should be available.
2. Agent should be enrolled on above Kibana environment.

Steps to Reproduce

1. Open the 7.10.0-SNAPSHOT Kibana cloud environment in browser, then click Ingest Manager.
2. Click on 'Fleet' tab to navigate to Fleet page.
3. Click on prerequisite Host and observe that error 'Agent not found. Cannot find agent Id <agent_id>' is displayed for a second before opening the activity logs successfully.

Test data
N/A

Impacted Test case id
N/A

Actual Result
Error 'Agent not found' is displayed for a second on clicking Host under Fleet tab and on refreshing the Activity log page

Expected Result
No error should be displayed on clicking Host under Fleet tab and on refreshing the Activity log page

What's working

• Issue is not occurring on 7.9.1 BC2 Kibana cloud environment

What's not working

• Issue is also occurring on refreshing the Activity log page for a Host under Fleet tab.

Screenshot

Logs

1. Browser console logs on clicking Host under Fleet tab:

   • #76613_browser_console_logs.zip
     

2. Browser Network logs response on refreshing the Activity log page:

   • 404 error with message 'The specified key does not exist' is displayed.
     

[elasticmachine]

Pinging @elastic/ingest-management (Feature:Fleet)

@manishgupta-qasource Please review the bug.

[manishgupta-qasource]

Reviewed & Assigned to @EricDavisX