If you don't have W2 available under Annual Forms (Taxes>Payroll Tax>Annual Forms), I'd recommend running your QuickBooks in a private window. This is to see if you're browser's cache is causing this unusual behavior. Here's how to start browsing privately.
For Chrome, press Ctrl+Shift+N.
For Internet Explorer or Firefox, press Ctrl+Shift+P.
Thanks for joining this thread. Allow me to help provide some update about the W-2 Form in QuickBooks Online (QBO).
We recently identified that some users are not able to pull the W-2 Form, and this is an ongoing issue in QuickBooks. Our engineers are already investigating the root cause of this unexpected hitch and working to implement a solution.
While we're continuing to work on resolving this issue, I recommend contacting our QuickBooks Online Support Team so they can add you to our notification list of affected users to receive live email updates about this issue.