I accidentally brought my bank account into QB twice, and then later merged the two. Now transactions both before the event and after the merge are gone from register.

Thank you for posting in the community, hfahle. I understand the importance of keeping accurate records for your business.

Please note that the account being merged may not keep the reconciliation history. This is why you are experiencing this issue. To fix this, we need to reconcile your account again in QuickBooks Online(QBO).

Here's how:

1. Go to Settings and then Reconcile. 
2. Click the Account dropdown, and select the account you want to reconcile. Make sure it's the same one on your bank statement.
3. Review the Beginning balance.
4. Enter the Ending balance and Ending date on your statement.
5. Select Start reconciling.

You can also refer to this article for more detailed information on reconciling your accounts in QBO: Reconcile an account in QuickBooks Online.

For future reference on arranging your transactions after reconciling your bank account in QBO, feel free to visit this article: Categorize online bank transactions in QuickBooks Online.

I'll be in the comment section for your responses. We're available for you 24/7 for more reconciling and QuickBooks-related inquiries. Stay safe. 

Thanks for the response, and I apologize for the delay in getting back to you, but I don't think that I worded my question correctly. I've been reconciling this account for years and everything was find until I accidenally brought it in a second time and then merged it. After the merge, there is only one option for this account (ending in nnnn) and I only show two transactions there. I think what I will do is just re-create the account starting balance for the time of the merge and sort of force it to work. I just don't see any other way.

Thanks again for your help!

Hello there, hfahle.

Thank you for sharing your insights on how to accomplish the task effectively. We appreciate your valuable input.

Feel free to get back to us if you have any other questions or concerns. We are here to assist you in any way we can.