The observed behaviour is that there is no data displayed when viewing analytics reports in the Analytics feature of the Layer7 API Developer Portal. There are no errors observed, just what appears to be a "lack of data", as if the data appears to be missing.
One root cause is a value that is too low set in the 'accumdata.maxBufferSize' CWP (cluster-wide property).
This can occur in any Layer7 API Portal versions 4.0 and newer.
It is important to ensure the value set for the 'accumdata.maxBufferSize' CWP is at least 500000000 or higher. If the value is too low, such as 5, the behaviour will be observed. To resolve, ensure the value is 500000000 or higher.
Reference documentation page for the Accumulate Data in Memory assertion: https://techdocs.broadcom.com/content/broadcom/techdocs/us/en/ca-enterprise-software/layer7-api-management/api-gateway/9-4/policy-assertions/assertion-palette/logging-auditing-and-alerts-assertions/accumulate-data-in-memory-assertion.html