I appreciate all the details you've shared regarding the issue you've encountered with sudden changes in bank dates when categorising transactions, treasurer4ric.

We can troubleshoot this type of concern by logging into your account using different supported browsers or private windows. This helps prevent issues caused by stored cache in cloud-based applications like QuickBooks.

If the issue persists, our live support team can securely review your account to identify the root cause of the issue. They have specialised tools and resources to investigate why transaction dates are changing unusually.

Here's how:

1. Sign in to your QuickBooks Online account.
2. Click the Help button.
3. In the QuickBooks Assistance chat box, select Talk to a Human or tap the Contact Us button at the bottom.
4. Type your reason for contacting us in the What can we help you with? section and click Continue.
5. From there, choose a way to connect: Chat or get a Callback.

Please check their support hours to reach them conveniently.

You can check this article in reconciling your account to avoid discrepancies in your records: Reconcile an account in QuickBooks Online

Should you need help managing your bank transactions, please let me know in the comments below.