I cannot override Memorized Payees in Investment Accounts, so I need to turn it off in Preferences, make my desired edit to a transaction, and then turn it back on in Preferences. For example, if I ever misspell the name of a Payee, the Memorized Payees service remembers the error and won't let me correct it. Then I need to turn off Memorized Payees, make the correction, and turn it back on. This problem does not occur in ordinary bank accounts, only in investment accounts.