More details would be helpful.
Is the ending date for the Net Worth report set to today?
Is th Net Worth balance different from today's balance in the register for that account? If different, make sure the register is sorted by Date.
Is it different from the balance in the Account Bar, usually on the left side of your screen? If different, click on the gear at the top tight of the Account bar and make sure it is set to “Show current balance”
Here are the steps I would follow to sort this out.
Please let us know what you find.