My Quicken Net Worth Report shows several investment’s values that differ from their Quicken account

Where in Quicken is the account balance different? 

Make sure the ending date for the Net Worth report is today.

If the balance is different on the Account Bar (usually on the left side of the screen), click on the gear at the top of the bar and make sure Show current Balance is selected.

If neither of those explains the difference, please post back for more ideas. 

I have just been through a frustrating period over several days tracking down an error similar to your description.
The NW (and the Act Balances reports were both off (low) for an Inv Acct.
The error started early May, 2022 and continued to date - nearly a year.
The portfolio Holdings was correct over this time period.

I was able to track the error down to a specific date and a specific transaction.
The NW and AB reports were ignoring a specific Buy transaction.
Editing or deleting/reentering the transaction had no effect.
Recalculating, validating etc, etc had no effect.

I did solve the issue - changed the date of the transaction, e.g. from 5/3/2022 to 5/2/2022.
BINGO - the reports snapped in.
Then changed the dat back to original date and reports remained OK.

Cannot see any ;logic to this solution but it worked.

Believe it does confirm some quirkiness in the reports.