Monitoring page only works if Elasticsearch is monitored

[LeeDr]

Kibana version: 8.3.0 (main)

Elasticsearch version: 8.3.0

Server OS version: Rocky8

Browser version:

Browser OS version:

Original install method (e.g. download page, yum, from source, etc.): rpm packages from snapshot build

Describe the bug: While setting up metricbeat monitoring a config mistake caused Elasticsearch monitoring to not be sent. But Kibana, Logstash, and Beats monitoring were working and ingested. But the Stack Monitoring page didn't show anything. Just a blank page.

Steps to reproduce:

1. install at least Elasticsearch, Kibana, and metricbeat
2. configure metricbeat to monitor Kibana
3. check Kibana Stack Monitoring page

Expected behavior: Monitoring data from other products should be shown in Stack Monitoring even if Elasticsearch isn't monitored or if Elasticsearch monitoring data is missing.

Screenshots (if relevant):

Errors in browser console (if relevant):

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

Any additional context:

[elasticmachine]

Pinging @elastic/infra-monitoring-ui (Team:Infra Monitoring UI)

[miltonhultgren]

This feels related to #125401

[LeeDr]

Yep, I'll close this one as a dup.