Mostafa, the behavior of screen pops is documented here:
https://help.mypurecloud.com/articles/screen-pop-in-genesys-cloud-for-salesforce/. I suspect what you're running in to is the softphone configuration within Salesforce, which governs what objects are searched when using either the ANI or the sf_searchValue screen pop method (FWIW, if no value is present in sf_searchValue, the integration uses ANI as the search value). The softphone settings also dictate the behavior of the Salesforce search and pop API in terms of what to do under the various possible scenarios; there are options for one record found, multiple records found, and no records found. I would double check the softphone layout that's assigned to your user to see if that's what is happening.
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Richard Schott
Genesys - Employees
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