Over time, our MFD went intermittent and then finally stopped working altogether. Not only is the display dead, but the buttons as well. Also, 6 months later, the cruise control went intermittent and then stopped working.
As for the power loss issues that's very common with those. We fix all the issues that these MFDs might have. Power loss is the most common where it doesn't turn on at all. As for the cruise control that's a separate function that is independent of the MFD. The brake light switch may be somehow not be triggering the cruise control but the MFD should not be affecting it.
You can use the link below to get your MFD repaired:
https://www.upfix.com/product/toyota-prius-2006-2009-mfd-navigation-radio-multifunctional-lcd-touchscreen-display-repair/