How to check off items during reconciliation?

You can always untick the transactions by clicking the bubble located on the right side of the screen, treasurer165. Allow me to provide further insights regarding your concern below.

Initially, when you're trying to reconcile in QuickBooks Desktop, transactions are automatically selected or deselected during reconciliation as you click on them, streamlining the process. QuickBooks Online, on the other hand, allows users to click on a specific transaction to view detailed information, offering a more thorough approach to transaction management during reconciliation.

You can refer to the screenshot I've provided below as a guide:

From there, you can select the preferred transactions that you want to modify during reconciliation.

Also, you can refer to this page below to have detailed information on how to reconcile accounts: Reconcile an account in QuickBooks Online.

Moreover, you can also check this page if you run into issues with accounts that have not been reconciled previously in QBO: Fix issues for accounts you've reconciled in the past in QuickBooks Online.

Lastly, you can take advantage of our QuickBooks Live Assisted, our Live Support team offers real-time assistance and provides guidance with any complication--from recording transactions to reconciliations. Let's enhance your financial management effortlessly. 

We aim to make your QuickBooks experience smooth and proficient, treasurer165. Please know that you can always revisit this thread if you have further questions about reconciling. We're always here to help.