From the point of view of MemTest86 (and any operating system running on the machine) I don't think load reduced DIMMs makes any difference.
Something that was strange however is the number of CPUs reported in your screen shot. It looks to be incorrectly reporting zero CPUs.
Can upload or send us the MemTest86.log file (under EFI\BOOT\ if running from USB). I assume you are running this from a USB stick.
Leave a comment: