hazelcast flake id returns different data

Question

I am trying to use the flake id instead of sequence in the database so that I can use the write-behind persistence mechanism. However I am getting this weird error where when I return the id as json the id changes but from postman it is fine.

Cache Code

long newId = hazelcastInstance.getFlakeIdGenerator("pk").newId();
meta.setId(newId);
getMetaCache().set(meta.getId(), meta);

Controller code

WorkflowMeta workflowMeta = objectMapper.readValue(request.getInputStream(), WorkflowMeta.class);
workflowService.saveWorkflowMeta(workflowMeta);

URI getUrl = HttpUtil.getRetrieveUrlForPostResponse(request, "/rest/priv/workflow/getWorkflowMetaById/" + workflowMeta.getId());
return ResponseEntity.created(getUrl).body("{\"success\":true, \"id\":" + workflowMeta.getId() + ", \"sucks\":true}");

For some weird reason, network->preview tab on chrome shows this:
{success: true, id: 115504597384036350, sucks: true}
network->preview tab

network->response tab on chrome shows this:
{"success":true, "id":115505723818901505, "sucks":true}
network->response tab

My UI code unfortunately picks up the previewed tab data which is wrong. Has anyone encountered this issue before or happens to know how to fix it?