We used to be able to add journal entries but now when we click the + nothing happens. Could this be a browser issue?

Hi there, accounts169.

When QuickBooks Online is unresponsive after clicking on the Plus icon, this behavior is caused by a browser-related issue. We can fix it by clearing the browser's historical data. 

Once done, log in to QuickBooks Online and click on the Plus icon. Select Journal Entry and enter the information.

There are more community posts and articles about making journal entry. If you have some time, you can check them in this link. 

Have a great day!