Transfer Mode "fail"

Seagate Barracuda HDD ST2000DM001 2TB. (Support Sata III 6GB/s)
Motherboard: Asrock fatal1ty z170 gaming k6 (Support Sata III 6GB/s)

Still, Sata II is going at 3GB/s with the Seagate HDD.

Next to it is a Western Digital WDC WD5000AAKX-001CA0 500GB and it is Sata III 6GB/s.

Why does seagate not bring the pace that she knows?

CrystalDiskInfo: https://imgur.com/a/LgANF5g

You should ask the Company Seagate, not us.
As you have verified, it is not an issue of your mainboard resp. its SATA Controllers and ports.

Thanks for the reply.
Sata controller is fine. 500GB WD goes in sataIII mode.
All ports of sata III Asrock motherboard. (think this you know)
I tried in each port.
Latest firmware on seagate.
So I don’t understand what the problem is.
I wrote here because I was hoping someone else might have such a HDD with a similar care.

@MexqQ :
As I already have written, I recommend to contact the Technical Support of Seagate.
Alternative: RMA the device (if possible).