3DS Payer Authentication Challenge/Stepup not working

[fruscitti]

Hi, I'm implementing Payer Authentication (3ds) and had a working version that today suddenly stopped to work.

When I submit the challenge in the challenge iframe, it post to: 

https://centinelapistag.cardinalcommerce.com/V1/TermURL/2.0/CCA

it is a form-encoded value with 2 fields. 

And then it gets a 400 - Bad Request as a response.

I don't know how to diagnose it, because it was working and is is generated by 3ds, not me.

Any idea how to see logs/something from cardinalcommerce?

The iframe post only to items that seems to be ok:

1. cres
   eyJtZXNzYWdlVHlwZSI6IkNSZXMiLCJtZXNzYWdlVmVyc2lvbiI6IjIuMi4wIiwidGhyZWVEU1NlcnZlclRyYW5zSUQiOiJhNmY5MGU1MS0yNzE5LTQwN2ItODI2Ni1lYjgwMDdjYjY2YmUiLCJhY3NUcmFuc0lEIjoiYTA1ZDRiODQtNWUxNC00YWYwLTgxNGYtOGNhNTVkNDM2N2NhIiwiY2hhbGxlbmdlQ29tcGxldGlvbkluZCI6IlkiLCJ0cmFuc1N0YXR1cyI6IlkifQ
2. threeDSSessionData
   MF9iNjEyYXXXXXXXXXXXXXXyMzU2YmU

Thanks very much.