I got an idea on how we can resolve your concern, Rozi Pozi.
Before we correct the mapping of the connected accounts, we'll need to undo the transactions that were added to wrong accounts. You can do by following the steps in this article: Unmatch downloaded bank transactions or move them to another account.
After undoing the bank transactions, we can now correct the mapping. We'll have to disconnect the bank account to remove the mapping of the accounts: Disconnect or delete accounts connected to online banking.
Then, we can reconnect the account to QuickBooks Online. This should now download the bank transactions to the correct accounts. From there, we can already categorize the transactions.
Keep us posted about this so we can further assist you in correcting your data.
