Welcome to the community family! QuickBooks Online is all about giving you control over your books. I'll be happy to show you how to pause or delete your automatic bank transfers.
From what you're describing, it sounds like you've either set up a Rule or Recurring transaction in your account. If your automatic bank transfer is scheduled as a recurring transaction, here's how you can stop it.
Select the Gear icon on the Toolbar, then Recurring Transactions.
Locate the transaction or template for the transfer in question.
Under the Action column, select the Edit drop-down, then Delete/Pause.
In case the transfer is set up as a Rule, simply go to Banking > Rules > Locate the rule for your bank transfer > select the Edit drop-down > DisableorDelete.
For more about recurring transactions and/or rules in the program, here are some articles.