new RAM is good, Precision 5510 errors 'memory limit exceeded' when both in

I have a dell precision 5510, got blackscreened trying to boot one day, so I reset cmos, no more blackscreens but almost immediately got BSOD, did ePSA testing and memory issues were detected.  I bought new RAM and decided to upgrade to 32 GB since that is max for the laptop (was at 16gb).  I put the new RAM in both slots, bootup was slow, I looked at system specs and it says '32 GB RAM installed, 3GB useable'

I troubleshoot the new RAM:

RAM 1 in Slot 1: boots fine, detects 16GB useable RAM

RAM 1 in Slot 2: boots fine, detects 16GB useable RAM

RAM 2 in Slot 1: boots fine, detects 16GB useable RAM

RAM 2 in Slot 2: boots fine, detects 16GB useable RAM

RAM 1 in Slot 1, RAM 2 in Slot 2: '32 GB RAM installed, 3GB useable'

RAM 2 in Slot 1, RAM 1 in Slot 2: '32 GB RAM installed, 3GB useable'

do ePSA with both ram in, I get 'memory limit exceeded'.  All troubleshooting I can find insists the RAM or the slots are bad, however also suggest that if the RAM in the slot boots and has useable RAM, the slot is fine.

I check BIOs is the latest version, checked there are no memory limits in the BIOs, checked the paging file is set to small and unchecked maximum memory in System Configuration > Advanced Options > Boot Tab

The memory when both are seated and detected but not useable, system shows as Hardware Reserved for the memory but I'm not seeing it reserved anywhere, and it only reserves when the 2 larger sticks are in.  Why?

I also did and ePSA with 1 RAM in 1 Slot and it passed, I did that for both sticks of RAM in both Slots, seems slots and RAM are good, and my system wants to reserve the memory but no indication of where it's reserved.   Can anyone help?

Precision 5510 limit is 32 GB