can someone check how fast the usb transfer speed is for Asus ROG Phone II? USB 3.1 speed?
To get 3.1 speed you need to buy a USB C 3.1 cable with 10gbit transfer (they can be quite expensive) and use the side port or you will get USB 2.0 speeds.
The bundled cable is USB C 2.0 and the main port is 2.0
Make sure it's USB C 3.1 Gen 2. Regular USB C 3.1 can only do 5 Gbps.
Also the Gen 2 cables are pretty short. 3 FT(1 m) is about the max length you can get. Any longer than that and you're probably being lied to.