HP Pavillion Laptop 2018, SATA drive entirely disappeared

Hello.

I am an IT manager, 30 years of experience. I have never seen this happen; My HP Pavillion Laptop Circa 2018, the SATA drive entirely disappeared. I mean, disappeared. Not just "corrupted", but gone. The laptop came with a 128MB SSD C: (System) drive and a 1TB SATA D: (data) drive. Up until 1 week ago, there was no sign of any issues. Then, I woke the computer up, and it said "Location D: is inaccessible". When I go to the device manager, it doesn't list that SATA drive at all....doesn't even detect it. I ran PC Audit, same thing. No sign of that SATA drive.

Anyone have any suggestions at all? The drive was not fully backed up, and there was data on it that I'd like to have back (most notably, it was the only place I kept the backup of the PREVIOUS laptop). I mean, I'm guessing somehow that the "bios" of the drive itself became corrupted? Is there any way to locate it or retrieve it? I used UBUNTU Linux to pull all of the data off the old laptop, but that drive was locatable, it was just inaccessible to Windows.

Any thoughts at all would be of great help!

Thanks,
Matt T