We have IDM configured with ServiceNow endpoint.
The configuration is IDM -> Layer 7 -> ServiceNow.
Seeing below response from ServiceNow in the Layer 7 logs: for all create and updates.
<head><title>400 Bad Request</title></head>
<center><h1>400 Bad Request</h1></center>
The problem is on the ServiceNow side. Please reach out to the Service Now support team to address the issue.