B450M Pro4 and MEMORY HX430C15PB3K2

Dear Sir/madam hello.

I have build it my PC a few days ago.
The system is stable and performs as expected except a strange behaviour when I enable XMP profile 1 (3000Mhz CL15-17-17-36).

The motherboard loads it successfully but fails to set correct the CAS Latency (CL) 15T ! ?
It's auto set to CL16T .

- Let me explain better.

The RAM I use, is in the list of supported memory (QVL)
The ram XMP Profile 1 sets timings at CL15-17-17-36.(as advertised by Kingstone HyperX Predator HX430C15PB3K2)
I used CPU-Z HWiNFO64 and AIDA64 to confirm my findings.

I have reset it the bios many times.
I removed the battery and power cable, I put jumper on Clear_CMOS pins for 15min.

I updated to the latest bios V1.60.
I removed all devices cables and memory sticks.
I reset Bios, Load Defaults etc...... No success, it always loads at CL16.@ XMP Profile 1
Then I tried to set manually the basic memory timings.

Firstly I tried to set the memory at CL15-16-16-36 , system booted successfully but the CAS Latency remained (CL) 16T.
CPU-Z,AIDA64 reported CL16-16-16-36.

Then I tried to set the memory at CL17-17-17-36, system booted successfully and the CAS Latency changed to (CL) 17T.
CPU-Z,AIDA64 reported CL17-17-17-36.

Finally I tried to set the memory at CL14-16-16-36, system booted successfully and the CAS Latency changed to (CL) 14T.
CPU-Z,AIDA64 reported CL14-16-16-36.

Can someone validate my findings?
Is this a bios bug or an incompatibility issue ?

Also i must mention my issue with the
"Arctic Freezer 33 plus" CPU cooler.
The fan doesn't start to spin before PWM is at 55-59% at CPU_FAN1 header.
When I put the fan to header CPU_FAN2 It starts to spin at PWM 10% ?

Is this a bug or a faulty header ?