Hi there, @Fili.Jo 👋
Sorry to hear that the Zap isn’t adding multiple owners. Presumably, it’s that Contacts DEMO field that you’re attempting to add them too, correct?
If so, it looks as though you’ve got the format of the field values correct, but the IDs in the different fields you’ve selected are the same—which could explain why only one contact is being added:

Can you try selecting a different ID for one of the Data Create Item Id fields, then retest the Update Item action to see if it adds the second contact as expected?
I see what you mean. However, I selected different Monday output and I do not know why it’s always the same ID in this exemple, It looks like it’s always only retaining one item id? Is it possible to “add” one instead resisting everything?
Hi @Fili.Jo,
Have you tried publishing the Zap and triggering it while it's live? Does the Zap still retain only one item ID during the run?
I'll be keeping an eye out for your response!