To be sure that this is nothing to do with privacy settings, you should tick the ignore privacy settings checkbox on your endpoint.
Also, to be clear, what I think Gaby was asking earlier was whether or not you had previously sent the offer’s unique id to RavePay as the tx_ref. It would be good to see a screenshot of the debugger showing that the tx_ref returned by the API call is indeed the same as the unique id of the offer found by the search.
One other thing to try, when you create the offer, could you set its txRef to its unique id then. Then for your search, instead of testing the returned tx_ref from the API call against the unique_id, you could test it against txRef. This is just in case Bubble is protective of unique_ids in some way.
Finally, even though I don’t think it matters too much, it is a little odd that you’re sorting the Offers search by modified date. There should be only one item with that unique id anyway, so no sort should be required.
Hope you get it sorted.