Intermittent Error - Request failed. 500: Internal Server Error

[PaulFreedman]

Recently i have been getting an issue with my 3 node Log Insight cluster running 8.1.0-15994158. When i login the dashboards all say 'Error Loading Chart' and when i try to check admin settings the top of the screen shows 'Request failed. 500: Internal Server Error'

It normally fixes itself after a reboot but i'm seeing this more and more regularly now. Anyone any ideas, or which logs i can check?

Thanks

[PaulFreedman]

Also this appears to only be occurring when accessing via the Integrated Load Balancer. If i access the UI via the master node it works as expected