In the HRM Case info widget in the Service Portal page "hrm_ticket_page", there is an option to ask a question regarding the case selected. It shows a connect popup. If there are user objects mentioned via @mention in the chat, only the sys_id of the user object is shown.
Release or Environment
All available releases
This is because the @mention functionality is not supported in the Service Portal. The following documentation explains the same.
The sys_id is displayed because the @mention APIs(which retrieve the user object) will not return the user object in the Service Portal. This is the reason why the sys_id is shown as a string. Here sn-chat widget is embedded in the HRM Case Info widget which is responsible for popping up the chat interface. There is a live_message entry(which is associated with the chat conversation) that has the same sys_id and it can retrieve the user object only by using @mention APIs. This would work only in the platform UI.
The @mention functionalities are only designed to work on the platform UI. There are other functionalities and scripts that work only in platform UI and not supported in Service Portal - like UI macros, Formatters etc.
If you try to refer a user via @mention functionality in the Service Portal, it will not work. If you have a user referred in the chat(in the platform UI), it will only display the sys_id of the user in the portal which is expected.
If you want the product team to consider implementing this, you can submit an enhancement request via our Idea Portal. Following is the link for the same