What are the dates of the missing transactions? Most banks sync with QuickBooks every 24 hours, but transactions older than 90 days won't download automatically and and need to be uploaded manually.
Also, check your credit card's website for any security alerts or notifications that might be causing a delay.
If the transactions aren’t that old and there are no issues with your bank, you can manually trigger an update by going to All apps > Accounting > Bank transactions and clicking Update.
For further questions or concerns, feel free to leave a reply below.