SAFEX C15 FSOE slave CRC error, while F3452 error at ctrlX drive side

Hi

I tried to use SAFEX C15 as an FSOE master, having a ctrlx Drive FSOE slave. My ethercat master is a VPB40, with Twincat runtime.

I used the following setup:

With this, I had the following error at drive :

I checked at Twincat the data  of FSOE, and I realized, that totally random numbers where changing at the SAFEX FSOE slave bytes.

SAFEX C15 provided SLAVE CRC ERROR

After changing ctrlX drive slave device in SAFEX to Indradrive CS Slave device everything started to work correctly.

Can you please give me some hints, how it is possible,that my ctrlx Drive works just with Indradrive CS slave device!