I had to re-authorise connection to my bank and now all previously reviewed transactions have been uncategorised

Hello, philiptarry-gmai. 

Thank you for reaching out to the Community. Once the transaction has been downloaded and reviews in QuickBooks from your bank, this prevents it from downloading duplicates when you reconnect it.  

When reconnecting, remember to select the date of the last transaction made with the account to ensure your transactions are up to date in QuickBooks. To learn more, Here's an article as your guide: How to re-authorise your bank connection. 

However, if you're unable to locate the transaction, you'll need to download your transactions as a CSV file from your bank. Then, import the data in your QuickBooks Self-Employed. Here's an article that includes the step-by-step process: Add older transactions to QuickBooks Self-Employed.  

If the same thing happens, Rest assured that our supports are available to help you fix this issue. You can visit this link to reach out to them: Contact QuickBooks Self-Employed Support. 

I've got your back if you need more help. I'm always happy to lend a hand. Have a good one. Stay safe!