Gigabyte z390 Aorus pro usb c port slow speeds

[Mezoxin]

This is my motherboard

https://www.gigabyte.com/Motherboard/Z390-AORUS-PRO-WIFI-rev-10#kf

when I use my usb nvme drive with the regular usb 3.0 ports even the front panel ones the transfer speeds is 400mb+ as with this picture

 

 

But when using the back panel usb c port with the same usb drive and the same file transfer , the transfer speeds are around 40mb , I used several usb c cables even the one included with the ipad pro 3rd gen , no change in speeds

and I have the latest drivers installed for my motherboard ,I tried googling  the issue  but failed to find a solution

[Ofir aviel]

Bed type c port on your motherboard maybe?

[Mezoxin]

according to the spec sheet it should be 1 x USB Type-C™ port with USB 3.1 Gen 2 support on the back panel

[Mezoxin]

I suspect most of the usb c to usb c cables i got might be usb 2.0 , but is the ipad pro 3rd gen usb c cable usb 2.0 as well  ??  because there is no mention of its specs anywhere seems like a very cheap move from apple considering its price , i will be ordering an amazon basics usb 3.1 gen 2 cable and see just to make sure