It’s possible that Round hasn’t updated to reflect your latest account balance. Where you see your linked account, you’ll also see when it was last updated.
Round grabs your balance at a few different points throughout the day which is enough for most people, but we appreciate for others you might need this to be a bit more regular.
You can always manually re-sync your account to get the most up-to-date balance and transaction date. Just hover over your account and tap ‘Reconnect’.