Yesterday I could add a product/service but today it just reboots me back to the sign in page.

I appreciate you for posting here in the Community, Carolina. I'll share some browser troubleshooting solutions to help fix the issue when adding a product or service item in QuickBooks Online (QBO).

One of the possible reasons why you're having trouble adding product/service items can sometimes be caused by a stored cache and cookies in your browser. Let's start by logging out of your account and logging back in, as it will help refresh the data in your account. After refreshing your company file, add your new products/services.

Furthermore, have you tried opening your account in private browsing to see if it's still showing the same behavior? This method prevents cookies from being stored on your computer, making it a great place to identify browser problems. Here are the shortcut keys:

• Google Chrome: press Ctrl + Shift + N
• Mozilla Firefox: press Ctrl + Shift + P
• Safari: press Command + Shift + N

Once you're in incognito mode, log in to your account and add a new product or service item. If it works, you can return to your regular browser and clear the cache to improve the program's performance. Otherwise, using other supported browsers can be a good alternative too.

Let me know the result once you've tried the steps. I want to ensure you can work with QuickBooks at its best. You can also notify me by hitting the Reply button below. It's my pleasure to help you at any time.