Let's do some troubleshooting steps so we can resolve this behavior, susanwellborn50.
We can update your SUI tax rate using an incognito window. Also, I suggest clearing the cache because this is also the reason why we experience errors in QuickBooks Online.
If you have other browser, you can also use it. Just make sure they are updated. You can read these articles for more details about QuickBooks Online Payroll Core:
Please reach out to our Payroll Specialists if you still can't update the tax rate. From the Help icon, click on Contact us and enter SUI tax rate in the question field. Select Let's talk and choose either Get a callback or Chat.
Keep on posting if you need further assistance. Wishing you all the best!