I am often tagging people on my team, and apparently I overuse doing this parenthetically, because I’ve learned that the people tag doesn’t work if it’s directly preceeded by a parenthesis.
In other words, “(@personName) will not toggle the people tag.
The workaround is to put a space between the parenthesis and @, but I believe this is not deeply intentional on your part, so figured I’d raise it.