@username in the comment or description doesn't notify the users

Question

When I attempt to use @username functionality, the usernames are not even listed to be selected. As I type @ the symbol turns Blue and the first word after also turns Blue , but the moment I hit enter/tab/space to continue with the sentence, the tag turns into a regular text. The system just treat that tag as regular text and doesn't recognize or notify that user.

Mohsen Vaseghi · Answer

Thanks Jack, I have done this and the result is still the same. We only have one project and all of the users I have tried are added to the project.

Jack Brickey · Answer

Can you ensure that the desired users actually have permissions to the project in questions? A good test is to see if the Assignee can be changed to another user and then use that user as a test in an @mention