Hi kristy-integrity,
Welcome to the QuickBooks Community! QuickBooks is a versatile program that enables you to get your work done faster. I'll be happy to provide some information on turning off automatic selection marks while reconciling your accounts.
To deselect all the transactions that are showing selected in your reconcile page, click on the very first selection icon to mass select (as shown in screenshot below):
This will unselect all of the transactions so you can go through each transaction one by one.
If you have any other questions, feel free to reply below. I'm happy to help.