When I try to add a new record via XML RPC API to a form that contains a subform, then the API call returns success, but the new record doesn't show up.

It doesn't matter whether I don't set the subform field (i.e. create a new main record without subform records), or whether create a subform record before and set the subform field of the added main record to the id of that subform record (i.e. create a main record with one subform record).

Adding records manually works well. I can also add records via API if I remove the subform.

Is there anything special about using the  XML RPC API  with subforms?

Thanks in advance and a Happy New Year,

Ute