Can you share with me how you add entries to your checking account? Are you using bank feeds to download transactions? Any additional information will help ensure a timely solution.
If the account is connected to bank feeds, I suggest reviewing the transactions before adding them to QuickBooks. The data that syncs into the system will depend on the information provided by your bank's website.
If there are any duplicates from the For Review tab, you'll need to exclude them. Here's how:
On the left navigation bar, click Banking.
Select the account.
Go to the For Review tab.
Put a check mark on the duplicate transactions.
Tick the Batch actions drop-down.
Hit Exclude Selected.
I also want to know the name of the financial institution you're having problems with QuickBooks. That way, I'll be able to check if there are any ongoing issues reported from other users.