New 16gb EEC MOMORY DONT funktion

[loudnbright]

Bougt Z4 Xenon with 32GB (4 x8 GB ECC modules).  Bough additional 2 x 16GB DDR 4 2933 ECC, product 5yz4aa  Customer service at HP said those work with Z4. When installing the Computer frezze, I also get strange reading at secure start, Like before 32GB, now 24GB, when installing 1 Memory, And when installed 2 iIt said total memory 40GB. But wont boot pass Bios.
I susspect it is wrong memorys in the packakge.  The Original HP packaging says 16GB DDR 2933 ECC  Part 5yz54AA

But on the memory itself it says (on both) M31174-591  . When browsing that i get 16G 3200 ECC. Is that even compatible with the Z4. 

[loudnbright]

It seems after some testing like one of the new modules are causing my problems. When installing only one of them, i du get the added  16GB memory and it boots.   if I Add the only teh other memory of 16GB together with the 32GB installed, the total memory is instead dropped to 24GB. So the memory cost me 8GB insteab of adding 16GB.  If Installing both, I get total 40 GB instead of 64, so no logic.

Rasises questions, is there any problem with HP packet 3200 EEC and labeled it 2933 EEC, as it seems to work with one of the  modules.    
Is it most likely this second memory module is faulty, than that there is a compatibility issue??