Hello there, @BSCCF.
Allow me to share information about voiding transactions.
In QuickBooks Online (QBO), once you void a transaction, it won’t affect your account balances or reports as you still have a record of it in your account. However, if you delete a transaction, it will be completely erased from your books and won’t appear on any reports or in any accounts.
Thus, you may need to do a new transfer transaction to offset the original transaction. Here's a resource for your guide: Transfer funds between accounts.
Additionally, to give you more idea about voiding transactions, here's an article that you can read: Void or delete transactions in QuickBooks Online.
Fill me in if you have other questions about handling banking entries in QuickBooks. I'll be happy to help you. Stay safe!