HELP RFID NXP NTAG

[SwissEngineer]

Hello everyone,
I'm not really good with RFID stuff so I am seeking some help!

I'm trying to have a design using the NXP NTAG I2C plus NT3H2111_2211 (http://www.nxp.com/documents/data_sheet/NT3H2111_2211.pdf)
I have the demoboard and everything works fine, now I wanted to use another antenna to suit my needs:
taoglas FXR.07.A.dg  (http://www.taoglas.com/wp-content/uploads/2016/11/FXR.07.A.dg_.pdf)
Because I need a round and with ferrite because I need to have it close to a steel product.

But I can't get it to work! I am using the same design as the demoboard, with just a capacitor of 56pF between the leads of the antenna, and going directly to the chip.

So what am I doing wrong?

Thanks!