I've seen other USB powered devices have the same problem. I think the Amazon Firestick specifically tells you to use their wall wart for power, do not use a TV USB port.
They work very differently too. MySQL's features vary significantly based on which engine is in use. They perform differently, have different relational abilities, store differently on disk (MyISAM is one file per table, InnoDB is one file for everything) and use different tools.