Reporting shows Forwarder is running but it fails to connect to any of the indexer

[#1]

In the current environment, all virtual machine devices are managed by a grid master, and the reporting service is enabled for 500m a day, which is normal after installation half a year ago, and there are always red alarms in the recent period: fails to connect to any of the indexers.

The firewall Settings are normal. Could you please check the cause for me? Thank you very much!

[#2]

maybe stop all of the reporting service on all appliances, then bring the reporting server back online, then enable reporting on each appliance one at a time?

you should probably  open a trouble ticket and let support check the support bundle.