[ale] UEFI/NVME system won't boot after dead CMOS battery

[Allen Beddingfield]

So, I have a fairly new Dell OptiPlex system with an NVME drive, and UEFI that is my issued "work from home" computer.
I am running openSUSE Leap on it.
I unplugged it prior to the lightning storm we had this morning, and when I plugged it back up, I got the signs of a dead CMOS battery (everything set to default, time not set, etc...).
So, I replaced that battery, set the time, and restarted.  I then get the UEFI screen that says the boot device is inaccessible.  I double checked that the SATA mode was set to AHCI, and it was - as it was before.
I can boot from an openSUSE disk, select the option to boot a copy of Linux from the hard drive, and it will start up my installation just fine.
I've tried re-installing the boot loader - no luck.
The partition scheme is simple.  #1 is the EFI partition, #2 is swap, and #3 is an XFS formatted "/".
This is the second time it happened.  Last time, I reset the time, forgot about changing the battery, and assumed the issue with booting was not related.  Apparently it is.  
It doesn't make any sense to me how a dead battery/bios reset could cause this, given that I double checked the SATA mode.  
I'm kind of stumped, and would like to figure out a way to keep this from being a future issue.
Any ideas?  
Oh, and secure boot is disabled, BTW.
Allen B.

--
Allen Beddingfield
Systems Engineer
Office of Information Technology
The University of Alabama
Office 205-348-2251
allen at ua.edu