No activity logs are displayed on installing agent on upgraded 7.10.0 BC2 cloud environment with 7.9.2 BC2 policy

Kibana version:
Kibana: Upgraded 7.10.0 Kibana BC2 cloud environment with commit f1c0bdd

Elasticsearch version:
Elasticsearch: Upgraded 7.10.0 BC2 cloud environment

Host OS and Browser version:
Windows , All

Original install method (e.g. download page, yum, from source, etc.):
7.9.2 Kibana BC2 cloud environment upgrade to 7.10.0 Kibana BC2 cloud environment from https://staging.found.no

Description
No activity logs are displayed on installing agent on upgraded 7.10.0 BC2 cloud environment with 7.9.2 BC2 policy

Preconditions

1. 7.9.2 BC2 cloud environment should be available.
2. Login into the above Kibana environment with 'elastic' superuser.
3. Agent configuration with name 'Rahul' and 'Rahul' should be created under "Configurations" tab in 7.9.2 BC2 Kibana cloud environment
4. 7.10.0 BC2 agent download from location on Host:
   https://staging.elastic.co/7.10.0-174bd372/downloads/beats/elastic-agent/elastic-agent-7.10.0-windows-x86_64.zip

Steps to Reproduce

1. Upgrade 7.9.2 BC2 cloud environment to 7.10.0 BC2 Kibana cloud environment
2. Click on "Fleet" link from L.H.S menu section and navigate to "Fleet" page.
3. Navigate to Policies tab
4. Install agent with ./elastic-agent install on Host using prerequisite 'Rahul' policy enrollment token.
5. Observe that no activity logs are displayed for above host under Agents->Host in Kibana.

Test data
N/A

Impacted Test case id
https://elastic.testrail.io/index.php?/cases/view/34209

Actual Result
No activity logs are displayed on installing agent on upgraded 7.10.0 BC2 Kibana cloud environment with 7.9.2 BC2 policy

Expected Result
Agent activity logs should be displayed on installing agent on upgraded 7.10.0 BC2 Kibana cloud environment with 7.9.2 BC2 policy

What's working

• Agent is in Online status

What's not working

• N/A

Screenshot

Logs
elastic-agent logs.zip

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

@vipulsrivastava-qasource Please review the bug

Reviewed and Assigned @EricDavisX

[EricDavisX]

@rahulgupta-qasource can you do an adjacent tests to give us more data on this please:

• if you create a new policy in 7.10 after upgrading does it work as expected on a similar host?

@nchaulet hi - any reason we can think of why 7.9 enrollment tokens would not work after upgrading the env to 7.10 and installing on a new agent? I think during a Beta we could get away with it... but for production use folks will def expect to be able to upgrade and continue to deploy with same policy / tokens right?

[nchaulet]

Normally 7.9 enrollment tokens should works in 7.10, looks like there is no POLICY distributed to the agent here I am investigating and able to have a repro locally

[nchaulet]

will be fixed by https://github.com/elastic/beats/issues/21904

[EricDavisX]

ok thanks. i'm moving this to Kibana repo then. cheers, and thanks for the quick fix.