Performing the steps provided by my colleague above is a good start, @treasurer140. In that manner, we determined that it is not a browser-related issue.

Let me add another way to rectify this matter. I have performed the same to see how it looks on my end when entering a bank deposit and selecting an account or category in QuickBooks Online (QBO). I see that there is a new interface that currently rolling out to some users. 

Thus, adding an account or category is different. You’ll want to follow the steps below to add them:

1. Click the + New icon and select Bank deposit.
2. From the Bank deposit window, select the Account section to see the dropdown. Then, tap see and add more categories hyperlink.
   
3. Under the All categories section, you can see all the existing accounts. You’ll only have to click the dropdown to see more.
4. Once selected the correct account, press the Select button.
   

That should enable you to add the account to its designated section. Another way around, you can type in the account name on the search bar under the All categories to add them. Furthermore, we have also received reports from other customers about the unavailability to select some accounts when entering bank deposits.

If you’re experiencing the same after performing the steps above, this may be caused by the ongoing issue. Hence, you can contact our Technical Support Team to ensure you get added to the list of affected users and get updated via email once a fix is available. You can inform them to add you to INV-83973 for easy tracking

Please let me know if you have other questions or concerns by leaving a comment below. I'm always here to help. Have a good one!