Get AUTHENTICATION_FAILURE code but can't know why.

Get AUTHENTICATION_FAILURE code but can't know why.

Hi all,

When I request Zoho API V2.0 in order to post records in the crm, I get sometimes the following error : 
{
    "code": "AUTHENTICATION_FAILURE",
    "details": {},
    "message": "Authentication failed",
    "status": "error"
}

And I don't know why.

Before each post, I request an new access token from the refresh token, I do my post then I revoke the access token.
It works correctly most of the time, but occasionally, it doesn't.
I found nothing in the documentation about errors returned.
Someone can help me please