@mention users is not working for some users on Azure Devops Board for work items [Azure]

Question

When editing or creating a work item for Azure DevOps Board, you can use "@" character to mention specific users. For some of my group members (Basic level), typing "@" doesn't present any usernames. According to Basic level access, only limitation published is access to Azure DevOps Test Plans. We're not trying to use Test Plans but merely editing/creating work item in Board and mentioning users. Does anyone know how to fix this? See screenshot below to see the issue

We tried changing access level from Basic to Visual Studio but that did not work as the user does not have visual studio subscription. Basic access does not limit use of Azure DevOps Board so not sure what is wrong here.

Answer 1

1. When you enter @ to trigger the @mention people picker in the work item, you see a list of users you've recently mentioned. If the user is not in the recently mentioned, you need to enter the name of the user you're looking for to do a directory search.

2. If you have searched the name of the user and still can't find the user, please check if your organization has enabled the Limit user visibility and collaboration to specific projects preview feature.
   For organizations that want to limit the search and selection to only those users and groups added to a specific project, they can do so by enabling the Limit user visibility and collaboration to specific projects preview feature for their organization. You can refer this document for more details: Limited identities in search selection