• Extension version: 0.23.1
• VSCode Version: 1.53.2
• OS: Windows 10

Steps to Reproduce:

Write a JSDoc-comment for a symbol:

/**
 * test
 * @param {string} e this line works
 * @returns {number | false} this does not work
 * @var does not work
*/

Notice that a GitHub user card appears on hovering over @returns or @var.
For @param it works