Hello DC_C. I recognize how this issue affected your accustomed routine. I know that tabbing over to the next line item was working for you in the past and significantly helped streamline your workflow. 

Upon checking, the investigation mentioned by my colleague is already closed and resolved. In this case, let's ensure first that your keyboard is working. If the issue persists, let's troubleshoot this together. An accumulated cache and cookies in the system can become outdated or corrupted, leading to unexpected behaviors.

To begin, open your account and create the transaction for which you need to use the tab key, using an incognito window to eliminate the possibility of a webpage issue.

You can do this by using the following keyboard shortcuts:

• Google Chrome and Microsoft Edge: Ctrl+ Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Safari: Command + Option + P
   

Once the tab key works, return to your regular browser and clear your cache to start afresh. You can also switch to other installed supported browsers, which is a good alternative.

Additionally, you can consider manually clicking the column to proceed with your task.

Moreover, I want to recommend some helpful resources for you to explore. These will assist you in effectively managing your QuickBooks Online account and streamlining the process of creating transactions:

• Adjust the QuickBooks homepage.
• Customize invoices, estimates, and sales receipts.
• Manage billing, payment, and subscription info. 

You can now use the tab key to navigate between different fields and line items, which can minimize errors and enhance efficiency. Your satisfaction is essential to us, and we want you to have a seamless experience. We're always here to assist and provide the necessary help you need, DC_C.