Placeholders from Zoho People isn't showing in organization signature

Placeholders from Zoho People isn't showing in organization signature

Hi,

I have setup an signature for my organization, and in the organization signature in mail admin panel I inserted
 {{ Mobile Number }} and {{ Designation }} which are from Zoho people Placeholders,

Most of the employees in the organization are missing the above information in their signature, yet for the other the info is inserted correctly,

what is the reason that some mails worked good (including my own) and rest of organization mails are missing any placeholders taken from people,
knowing that all users have access to zoho people and their accounts are configured correctly for "Designation" and "mobile number" info (meaning that their info are not missing from Zoho people)
and all the integration extensions in zoho mail to zoho people are enabled.