I experienced the same issue. The BSODs started to occur more and more frequently. Each time the BIOS couldn't locate the SSD for a while. I managed to solve the issue by replacing the SSD with a Samsung 970 EVO Plus 2TB. The replacement was a bit difficult, so Corsair should make a guide. In short as I remember it, it was done like this:
Open the top lid by pressing the button in the back.
Detach the fan cable and put the fan aside.
Open side panel where the graphics card is located.
Unscrew something like 6 to 8 screws to losen the card.
Detach the wide cable to the left that I think connects the main board and graphics card.
Then it is possible to partially lift the graphics card up to reveal the SSD in the middle.
The SSD is fastened with one golden screw. Unscrew and pull the SSD out.
Replace with the new SSD and put it all together again.