Let's try to find out why your accounts got out of balanced.
We can pull up the Audit Log report to check if there are activities made for the past days. Please click on the Gear icon and select Audit Log. You can also see the user name who made the changes.
Once you found out that transactions were changed, open each of them and update the information. That could be the reason why the accounts got unreconciled.
I would also suggest adding password in your reconciled/closed books. It helps to prevent any changes that may happen. Please refer to this article for the steps: How To Close the Books.
We'll be right here if you have any questions.