No SMART reports for some of cache SSDs

Hello, on my Unraid 6.12.8, I have 2 1TB nvme SSDs from the same manufacturer, acting as cache using BTFS 

I recently noticed in the logs that apparently one of the SSDs might be dying.

Mar 13 18:35:13 f kernel: btrfs_end_super_write: 282 callbacks suppressed
Mar 13 18:35:13 f kernel: BTRFS warning (device nvme0n1p1): lost page write due to IO error on /dev/nvme0n1p1 (-5)
Mar 13 18:35:13 f kernel: BTRFS error (device nvme0n1p1): bdev /dev/nvme0n1p1 errs: wr 326893147, rd 40441477, flush 23342600, corrupt 3, gen 0
Mar 13 18:35:13 f kernel: BTRFS error (device nvme0n1p1): error writing primary super block to device 1
Mar 13 18:35:13 f kernel: BTRFS error (device nvme0n1p1): bdev /dev/nvme0n1p1 errs: wr 326893148, rd 40441477, flush 23342600, corrupt 3, gen 0
Mar 13 18:35:13 f kernel: BTRFS error (device nvme0n1p1): bdev /dev/nvme0n1p1 errs: wr 326893149, rd 40441477, flush 23342600, corrupt 3, gen 0
Mar 13 18:35:13 f kernel: BTRFS warning (device nvme0n1p1): lost page write due to IO error on /dev/nvme0n1p1 (-5)
Mar 13 18:35:13 f kernel: BTRFS error (device nvme0n1p1): error writing primary super block to device 1

When I click on the device name and then go to the Self-Test tab, and then click on Download, a .zip file is downloaded and inside it, there is a TXT file, that contains the result of the SMART analysis.

It turns out that only on 1 of the SSDs, the TXT file contains the SMART test report, on the other SSD the TXT file only contains

 

smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.1.74-Unraid] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org

Smartctl open device: /dev/nvme0 failed: No such device

Questions:

1 - Is this a bug?
2 - Why apparently only 1 of the SSDs is being used? ( Cache 2 is used but the )
3 - In the Self-Test tab of Cache 2, when clicking SMART error log, the error is displayed:

Num   ErrCount  SQId   CmdId  Status  PELoc          LBA  NSID    VS  Message
  0        106     0  0x0001  0x4004      -            0     0     -  Invalid Field in Command

Why is the error not counted in "Pool Devices" -> "Errors" column?

Some extra information:

 

root@f:~# cat /etc/unraid-version 
version="6.12.8"

root@f:~# mount | grep nvm
/dev/nvme0n1p1 on /mnt/cache type btrfs (rw,noatime,ssd,discard=async,space_cache=v2,subvolid=5,subvol=/)

root@f:~# ls /dev/ | grep nvm
nvme1
nvme1n1
nvme1n1p1

Cache 1:

Cache 2: 

.