Why are product codes which have been on the system for years not being recognised when creating invoices?

Hello bbtb25, thanks for reaching out to the QuickBooks Community today

We're aware that some of our UK customers are currently unable to use the drop-down options in QuickBooks Online and our team are actively working on resolving the issue.

We'll update this thread once a fix has been confirmed and apologise for any inconvenience being caused in the meantime. 

Thanks for your patience.  This issue is now resolved, please reply to this post if you continue to see anything different.