Search Contacts API returning 204 response when trying to fetch the contacts based on phone number. It is working abnormally.

Sometimes when i try to hit the api it return the contact but soetime it returns the empty repsonse with 204 status.

Bellow is the api that i'm using:

https://desk.zoho.com/api/v1/search?searchStr=1111111111&module=contacts

I have check the auth tokens and all the other stuffs and nothing is working. Please help me with this issue.