I initiated a system exchange and with the new system all the m2 SSD slots now show full speed as expected.  So, not sure what the issue was with the board on the original system but the replacement is working as expected.  Dell's support was stellar in getting a replacement system without any hassle.
I have a 3460 SFF that I added 2 additional nVME SSD drives to the open m2 2280 slots.  One of the drives is new WD 850x.  All the reviews/testing of this drive show that is should easily hit 6-7K MB/s but I'm seeing around 1800 MB/s.  in CrystalDiskMark.  I contacted Dell support but because the drive was not purchased from them, they are unwilling to help/support.  I'm running Windows 11 Professional with all the latest drivers, BIOS, etc. Any thoughts/ideas on why I'd be seeing decreased performance? Thanks for the help!
Precision 3460 SFF nVME slow transfer rates