GH4 and white-balance / colour-profile issue with colour chart

[DamienMTL]

Hello,
I bought a colour chart at greywhitebalancecolourcard.co.uk few months ago and I have some trouble using it with my GH4.
Before that, I used my friends' gretta mcbeth chart without major problem, 18% plain grey sheet and sometime used an x-rite colourchecker passeport.

With this colour chart, I have some trouble to even set up the white balance properly and consistently.
I used the card this weekend for a session and shot some charts as required.

My strobes are delivering consistent 5600K white flashes according to the manual, I used a 4 point lighting setup with all the same strobes, same age. I shot some pictures of the card in RAW. (files available to download):

http://chart.dyrec.com/colourchart1.dng
http://chart.dyrec.com/colourchart2.dng

We then used the white balance tool in PS or Lightroom.
The 3 first monochrome squares give me :

1. 6830K / +3
2. 6600K / +5
3. 6300K / 0

I don't know why, but it's like if the colours on the chart were off.

I can see the printing structure on the colour squares, and pixel-peeping is a bit random since one pixel is different to the next one.
So I shot a second time the chart but without focusing to blend the details. I have nearly the same bad results.

>>> How is it possible to have 3 different colour temperature for the 3 first white-to-black squares? It's a difference of 530K which is a lot.

>>> How is it possible to have my white balance determined at around 6500K with strobes delivering 5600K white?

That would be so nice if you could share with me your insight about that? I don't know what to trust, my camera, the software values, or the calibration chart?
thanks

[Richard Wait]

Sorry to dig up an old thread. But I'm looking at these cheaper cards. Did you get anywhere with them?