M.2_2 drive keeps disappearing

I have an ASRock B365M Pro4 motherboard &a Samsung 970 EVO Plus 500GB M.2 NVME for the OS & programs. I just installed an EVO Plus 1TB in the M.2_2 slot to use as D: storage drive.

Initially it worked & I was able to copy a few files to it from an EHD, but the next day I could not copy to it and kept getting Error 0x800701B1. I tried different USB ports & another EHD but to no avail.

I rebooted the PC and the D: drive no longer showed up anywhere, including in disk management.

The next day I re-seated the M.2_2 memory & when the PC powered up a message came up saying it was fixing a problem. It took only a few seconds & the D: drive then appeared. Everything worked & I copied some more folders to the drive.

The next day (today) when I turned on the PC the D: drive was not there again.

I didn?™t make any changes & rebooted the PC & a message came up saying something about a stop problem & I should make a note of the error code. It also said it was repairing a problem. This caught me off guard & came & went so quickly I wasn?™t able to read the whole message let alone write down an error code.

But everything is acting normal & the files I previously copied to the D: drive are still there. Bios does show both M.2 slots have the Samsung drives.

Any idea why the M.2 D: drive disappears for no apparent reason? Defective drive or mobo?

Any help would be appreciated.
Thanks.

I thought about doing a BIOS update but did not. The ASRock website said don't do it if you are not having a problem. Since the C: drive did not have a problem with an EVO Plus in it I was thinking the BIOS has to be working OK. I figured a BIOS update would be my last resort.

Everything has been working OK since that last error message & that a problem was being fixed. Wish I knew what was being fixed.

I also updated the Samsung driver to a new version.

What Health report should I run?