Did you try what in the first link, if not do it.
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.