REST API throws HTTP 404 55 error intermittently

We have recently implemented REST API Inbound call to Siebel via Mulesoft integration. Intermittently Mulesoft is seeing Http 404 error at their end, similarly we are seeing similar error in Siebel Tomcat logs:

10.32.xx.xx- - [20/Jun/2024:09:06:11 -0500] "GET /siebel/v1.0/data/abc%20EasyParts%20SolNav%20Lookup%20BO/JCI%20EasyParts%20SolNav%20Lookup?PageSize=100&searchspec=%28%5BJCI%20abc%20Id%5D%3D%271-1PB0FHT5%27%20AND%20%5BJCI%20Record%20Type%5D%3D%27Address%27%29 HTTP/1.1" 404 55

Request is successful at time, HTTP 200 success records are there.

Intermittently we are seeing HTTP 404 55 error, any idea what else we can check to narrow down the cause of this issue.

Thanks in advance for any input.