If you have one real-world brokerage account that hold securities, receives dividends, and these 'interest' deposits, et al. Your options for the "Savings account" would betreat it as a MM securityrecognize the cash balance in the Quicken account as the balance in the "Savings account" as you have tried, create a separate Quicken account transferring cash back and forth between the brokerage account and the "savings account".Personally, I'd likely go #1, and I know others would go #2 route. For that #2 route, you can still enter a MiscInc transaction for any amount and assign it to an appropriate category (_IntInc, Interest:Bank, Misc Income, ...) You would not have to assign a 'security' to the income.
If you have one real-world brokerage account that hold securities, receives dividends, and these 'interest' deposits, et al. Your options for the "Savings account" would be