Your personal and business transactions will auto-categorize in QuickBooks Online if the bank rule feature is enabled. If you don't enable it, you'll need to manually categorize the transaction as personal withdrawal or transfer.
To check if you have set up a bank rule:
Click on the Transactions tab.
Click on Rules.
From here you will see if there is a bank rules set up to categorise
Under the Transactions tab let's click also the settings if Show suggested rules and enable suggested categorisation is ticked. Here's how:
Click on the Transactions tab.
Click on the Settings icon above ACTION.
Check if Show suggested rules and Enable suggested categorisation is ticked.