I try to send the data from a Newsletter form from webflow via Make (Integromat) to Sendinblue. All data is submitted between the systems but only the option field for salutation (Frau / Herr) is not.
I’ve never used Sendinblue but yes, I’d assume that would have to be an exact match.
What stands out to me, in your screenshot, is the ones that currently work are of attribute type “text” whereas the one that fails is of attribute type “category” (which has a different button than the other category type - something is different about it).
Play around with that. Match the ones that work to the one that doesn’t.
Also, did you look at what that error message means from their API docs?
Chris alluded to this as well- my guess would be that the salutation you’re trying to submit does not exist in your Category list that you have assigned to your SALUTATIONs. The API call is failing because it cannot add the contact information you’ve provided.
For what you’re doing I’d guess SALUTATION should be changed to attribute type Text
If that doesn’t work you’ll want to contact Make.com support, or SendInBlue supporrt, since they can see inside of your API transaction better.