Quicken for Mac routinely populates variable fields (Notes/Memos) with random past entries, while recurring entries (Advisor fee) are left blank. Why does this never get fixed?
I don't think Quicken will ever populate a transaction amount based on previous entries. If you have a recurring investment fee in one of your accounts you can set up a scheduled transaction for it as long as it's just removing cash from the account (you can't schedule buy or sell transactions).
You may be having QuickFill rules automatically created. Go to menu Quicken > Settings (Register) and uncheck the box
Then go to menu Window > Payees & Rules, click the QuickFill Rules tab and delete or edit any unwanted QuickFill rules.
