Aurora R11 RAM upgrade failure (DDRs all work when do as 2, Amber Post 4 blinks with 4 )

Trying to expand the memory from 32GB to 64GB with 4x16GB Corsair DDR 3400 chips 16 GB chips.  Have had two in for 32GB the last year.  Purchased matching DDR, did standard power down, add DDRs fails POST with 4 amber blinks.

Proceed to test DDRs, replace working two in mem slots 1&4 (XMM1&2)(White clips) way it was configured from factory with new mem chips.  boots fine, sees 32GB.

Power down, remove new DDRs, put in old chips in slots 2&3. (Black clips) Close, boot.  Boots, get memory change message, continue, comes up fine, sees 32 GB. 

Power down, add all DDRs, boot, 4 Amber blinks on PoST.

Look at manual it lists memory slots 1&2 to be used in table which are the middle two slots one white clips, one black clips but separate note for 1&4 if two DDR .  So power down do it again. take out chips, put new DDR in slots 1&2 (one white/one black clip), close boot, get memory change, continue, boots thru, sees 32 GB.

Power down, add all DDRs, boot, 4 amber blinks.

Each set of DDRs work in and paired set of memory slots, but all four DDR don't work when in all for slots even though manual says 4x16 is supported. 

I feel like I’m missing a magic secret handshake to get it to see four chips.   Help please.