Review on USB C Female to Female Adapter (2 Pack) PD 100W Quick Charge Type C Coupler Extender Extension Connector for Thunderbolt 3 MacBook, Nintendo Switch, Samsung - Cellularize by Mark Caperton

This does exactly what it's supposed to do. It connects two male USB-C ports. You may need to flip one of the male ports upside down when using it to connect wire to wire, but that's not the female/female port's fault. The USB-C wire specification only connects about half of the pins. So if they don't line up, the data pins won't be connected across both wires.