WD BLACK SN750 problems

Hello,

I have purchased two 500 GB SN750 NVMEs. One of them with heatsink, the other one without heatsink (only reason, availability on Amazon).

Both of them are installed on a PCIe adapter, and into HP Microserver Gen8 servers.

Server 1 works perfectly. I run FreeBSD and I could format the NVMe to 4096 byte sectors without problems. It is working like a charm.

Server 2, however is having trouble. Whenever I try to write anything I get errors.

Error Information Log                                                           

=====================
Entry 01

Error count: 9
Submission queue ID: 3
Command ID: 112
Status:
Phase tag: 0
Status code: 4
Status code type: 0
More: 1
DNR: 0
Error location: 65535
LBA: 65929785
Namespace ID: 1
Vendor specific info: 7
Transport type: 0
Command specific info:0
Transport specific: 0
Entry 02

Error count: 8
Submission queue ID: 1
Command ID: 47
Status:
Phase tag: 0
Status code: 4
Status code type: 0
More: 1
DNR: 0
Error location: 65535
LBA: 65929785
Namespace ID: 1
Vendor specific info: 7
Transport type: 0
Command specific info:0
Transport specific: 0
Entry 03

Error count: 7
Submission queue ID: 4
Command ID: 127
Status:
Phase tag: 0
Status code: 4
Status code type: 0
More: 1
DNR: 0
Error location: 65535
LBA: 65929785
Namespace ID: 1
Vendor specific info: 7
Transport type: 0
Command specific info:0
Transport specific: 0
root@:~ #

At first I thought I had a defective unit, so I returned it to Amazon for a replacement. The replacement (again, without heatsink) is showing the same problems. I only get errors when trying to write, reading works perfectly.

The only difference between them I can see is firmware.

The one that works is running 102000WD.

The problematic one is running 111110WD.

Is it possible to obtain the 102000WD version firmware in order to update the problematic one? (or, more accurately, downgrade).

Both servers have the same hardeware configuration, BIOS settings, etc.

Any clues?