Why is my laptop doesnt read my SSD?

Laptop automatically boots into BIOS and SSD not detected intermittently

My laptop suddenly shut down, and when I turned it back on, it booted directly into the BIOS. In the BIOS, only the HDD is detected—the SSD doesn’t appear. I tried removing and reinserting the SSD, and it worked again for a while. However, the issue keeps happening repeatedly. I'm quite sure the SSD itself isn't faulty since it's still being detected at times. I suspect the SSD port (slot) might be the problem.

What can I do to fix this issue permanently? Thanks for helping in advance.