3407593 - Real time sync fails with status: Error occurred while publishing the event to the destination endpoint...

The Real-time Synchronization of new hires from SF to IAS through IPS is successfully creating the users in IAS. Nonetheless, when reviewing the pre-delivered integration in the integration center, the Real-Time Sync status remains "in progress.".
After some time/days, the sync job transitions to a "failed" state, accompanied by the error message specified: "Error occurred while publishing the event to the destination endpoint. Business Key: xxxx. URL: [Insert URL].".
Consequently, the new hires does not receive their account activation emails. 

SAP SuccessFactors HXM Suite

INC6452868, INT-17256, real time sync, timeout, IPS endpoint, email, new hires , KBA , LOD-SF-PLT-IAS , Identity Authentication Services (IAS) With BizX , BC-IAM-IDS , Identity Authentication Service , BC-IAM-IPS , Identity Provisioning Service (IPS) , LOD-SF-OBX-IAS , IAS User Authentication , How To