Welcome to the Community. QuickBooks Online is a great program that gives you the ability to easily track your sales and expenses. I'd be glad to help regarding tax codes.
I encourage you follow these steps to troubleshoot the issue you've described.
Clear app data. To do this:
Open your device Settings.
select Apps (varies by device).
Choose QuickBooks app from the list, then select Storage.
Select clear data.
Power down and restart your device.
Uninstall and reinstall the app.
If the steps provided above don't work, I recommend that you contact our customer support team. They'll be able to take a closer look at your account. Here are some options available to reach out to our team.
Phone: Call us at 1-855-253-1536
Schedule a Callback or start a Chat: click (?)Help in the upper right in QuickBooks Online > type and enter "Contact support" into the QB Assistant > click Contact Us > explain your situation > click Let's Talk > choose Get a callback or Start a Chat.