The issue is now resolved.

1. Replaced boot ssd for a new one.
2. Installed Truenas on said ssd.
3. Imported config/db.
4. Unlocked encrypted datasets on data drives.

Really straightforward with Truenas. Thanks to those who took the time to reply 👍

Output of journalctl is almost same as dmesg:

dec 04 05:22:58 mx kernel: usb 2-1: new SuperSpeed USB device number 17 using xhci_hcd
dec 04 05:22:58 mx kernel: usb 2-1: New USB device found, idVendor=2109, idProduct=0711, bcdDevice= 1.44
dec 04 05:22:58 mx kernel: usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
dec 04 05:22:58 mx kernel: usb 2-1: Product: VLI Product String
dec 04 05:22:58 mx kernel: usb 2-1: Manufacturer: VLI manufacture String
dec 04 05:22:58 mx kernel: usb 2-1: SerialNumber: 000000123AFF
dec 04 05:22:58 mx kernel: usb-storage 2-1:1.0: USB Mass Storage device detected
dec 04 05:22:58 mx kernel: usb-storage 2-1:1.0: Quirks match for vid 2109 pid 0711: 2000000
dec 04 05:22:58 mx kernel: scsi host3: usb-storage 2-1:1.0
dec 04 05:22:58 mx mtp-probe[31054]: checking bus 2, device 17: "/sys/devices/pci0000:00/0000:00:14.0/usb2/2-1"
dec 04 05:22:58 mx mtp-probe[31054]: bus: 2, device: 17 was not an MTP device
dec 04 05:22:59 mx mtp-probe[31084]: checking bus 2, device 17: "/sys/devices/pci0000:00/0000:00:14.0/usb2/2-1"
dec 04 05:22:59 mx mtp-probe[31084]: bus: 2, device: 17 was not an MTP device
dec 04 05:23:20 mx kernel: usb 2-1: reset SuperSpeed USB device number 17 using xhci_hcd

This cable has connected fine to previous ssd’s.
Maybe the drive just had a typical ssd reactive failure 🤔
(Disk Manager is just a gui mount tool shipped with mx.)