NVMe device dropped offline, power cycling the server (not just rebooting) should bring it back, sometimes this helps with this issue:
Some NVMe devices have issues with power states on Linux, try this, on the main GUI page click on flash, scroll down to "Syslinux Configuration", make sure it's set to "menu view" (on the top right) and add this to your default boot option, after "append" and before "initrd=/bzroot"
nvme_core.default_ps_max_latency_us=0
Reboot and see if it makes a difference.