3348272 - Frequently calling API endpoint created in SAP API Management fails randomly with HTTP 403 - Forbidden error

Frequent calls to API Management where CI iflow endpoint is maintained as target endpoint fails. Sometimes the call works, sometimes it ends with HTTP 403 Forbidden error. 
When the error happens, the CI iflow endpoint is not reached, there is no message generated in Message Monitor. 

In the API Management, when troubleshooting the issue via Debbugger Mode , below error can be found:

error: Received non success response code 
type: ErrorPoint
state: TARGET_RESP_FLOW
error.class: com.apigee.errors.http.server.BadGateway

When checking the CPI iflow maintained under target endpoint, in the sender channel CSRF-token is enabled, meaning the CSRF token will be needed to call the endpoint from API Management side. 

SAP API Management 
SAP Cloud Integration 
SAP Integration Suite

x-csrf-token, x-csrf-token:required, session cookie, CSRF token, SAP API Management, HTTP 403, Forbidden error, error: Received non success response code , type: ErrorPoint, state: TARGET_RESP_FLOW, error.class: com.apigee.errors.http.server.BadGateway, cloud integration, integration suite, , KBA , OPU-API-OD-RT , Runtime , OPU-GW-COR , Framework , Problem