Hi there lisa222,
The Memo field is currently available for Expenses and Bills. You can use the memo field to add more details on a client transaction and for you to easily track what the transaction is.
There are different reports that you can run like Transactions List by Date or Transaction List by Customer to see the entire information of the transaction. Here's how:
Feel free to reply on this thread if you need any help. Have a nice day!
Aside from Expenses and Bills, the memo field is also available in Receive payment, Delayed credit, and Delayed charge. I need more information about the information you've stated about " used to work and appears to be disabled". Can you share what specific transaction did you see the memo field before? Any information is much appreciated so I can provide the best solution.
I've also included this article for future reference: Customise invoices, quotes, and sales receipts in QuickBooks Online. This contains helpful information on how you can change the layout of your sales form to show only the information that matters most to your business.
I'll keep an eye on your response, please don't hesitate to reply to this post. Take care and stay safe.