Nice to have you joined this thread, @joedrum.
I've checked here on my end and found out the investigation is still in progress. Rest assured our engineering team is working diligently for a permanent fix.
In the meantime, I recommend contacting our support team. This way, you'll be added to the list of affected users and be notified via email of any updates. You can refer to the steps shared by my colleague Giovann_G above in reaching out to them.
Furthermore, I'm adding this article that can guide you on how to import transactions to your account: Add older transactions to QuickBooks Self-Employed (QBSE).
Please bear with us as we're working to fix this. If you have any other concerns about mileage and QBSE, please let me know in your reply. I'll be more than happy to help. Stay safe!