Hi, everyone!
Our team is currently experiencing issue where our apps deployed in ArcGIS Enterprise are not loading properly when accessed by multiple users simultaneously. Some layers in our apps are taking too long to load and eventually throws a data source error and an error 500 when we checked the developer tools. (Please see screenshots below)


We also checked the Portal logs and encountered "The hosting server may not be reachable." message. (Please see screenshot below)

We have not experienced this issue before where multiple users accessed simultaneously. We just encountered this issue since yesterday.
Here are some of the workarounds that we did in attempting to resolve the issue, but still no luck:
• Monitored the server CPU and RAM, but all seem stable
• Restarted services consumed by apps in ArcGIS Server Manager
• Restarted all ArcGIS Enterprise components in Windows Services
• Already installed necessary patches
• We also performed speed test and connection seems fine
By the way, our apps are deployed in ArcGIS Enterprise 11.4 which is in AWS cloud.
Has anyone encountered this issue before?
I appreciate any ideas on how to resolve this. Thank you very much.