@Iñaki Ruiz You could try the Pega 23.1.5 Patch Release Pega Infinity '23.1.5 - Patch Release Available! | Support Center

@Iñaki Ruiz

that hotfix is about migrating any remaining Hazelcast (HZ) use to Pega’s newer clustering approach in 23.1.4. First, confirm it applies by checking your Upgrade Scan/Guardrails report for Hazelcast references or “cluster” warnings and by searching the hotfix ID in My Pega Support; if it’s flagged as Critical Missing, assume you need it. Request HFIX-C1343 from Pega Support and install it in a lower environment using Hotfix Manager, then restart all nodes. After install, validate cluster health: nodes join cleanly, no Hazelcast jars load, and Pulse, queue processors, job schedulers, and real-time containers run without errors. Do a quick failover check by stopping one node and confirming assignments, locks, and sessions behave normally. Regression test case creation, work routing, and background processing; watch PDC for new alerts/errors. If everything is clean, promote to higher environments with a rollback plan and document DSS/rule changes noted in the hotfix readme.