There are times that the browser stores a frequently-accessed data, thus websites, like QBO, to act unusual behavior.
I suggest logging in to your QBO account using a private browser. Browsing privately disables the cache from saving your browsing data, and it's a good way to check issues caused by a full cache.
To use a private browser, here's how:
Google Chrome: Ctrl + Shift + N
Internet Explorer: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + N
Safari: Command + Option + N
Once logged in, go back and try to reload your employees page.
If you get the same result while using a private browser, I recommend switching to a different one.
Please check this article on how to easily add or make any changes on the employee's information even without subscribing to payroll: Add, edit, or inactivate an employee.
Please let me know if you have other questions related with QuikBooks. I'm always here to help you.