Issues with tax calculation in federal tax withheld showing as zero when generating paycheck can often be fixed by performing some basic troubleshooting. Let's begin by accessing your account in a private browser. Since this type of browser doesn't store cache, it's easier for us to identify if this is a browser issue.
Follow these keyboard shortcuts to start an incognito session:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Shift + N
Microsoft Edge: Ctrl + Shift + P
If it works, you may want to clear the browsing history of your regular web browser. This will remove previously stored browsing data that might have caused the issue. Otherwise, you can try using other supported browsers to be thorough.
In the meantime, you can check the following article for some links about the payroll tasks in QuickBooks Online: Payroll Resource Hub.
You can also visit our QuickBooks Help Articles page if you need some reference in completing your other tasks.
Be sure to get back to me if you have additional questions. It would be my pleasure to help. Have a good one!