Right now, we haven't received similar issues about a sales tax center malfunction. No worries, I've got some tricks to ace this and get you back up again.
Based on your scenario, I can see that you're accessing the sales tax center both on the QuickBooks Online (QBO) desktop app and the web browser. I know the different set of steps you can perform for both of them.
To start, let's try to refresh your browser. To do this, click the Reload icon beside the QuickBooks URL or press CTRL + F5 on your keyboard.
If you get the same result, you can use a private browser (incognito) when accessing your account. QuickBooks uses cache to remember frequently visited websites. This way, you can save time and load pages faster.
However, they become outdated or corrupted when piled up. Thus, it can cause QBO to act weirdly, like the spinning wheel you're seeing when accessing your sales tax center. Private mode disables cache and browser cookies, hence a perfect place to fix issues like this.
The following are the shortcut keys you can use to access one:
Ctrl+ Shift + N for Google Chrome .
Ctrl + Shift + P for Mozilla Firefox and Microsoft Edge .