Hello and thanks for your help.
I checked the offer by trade_id. It's not empty.
{"response":{"trades":[{"tradeid":"4120244556543804085","steamid_other":"76561198235183636","time_init":1654976889,"status":3,"assets_given":[{"appid":252490,"contextid":"2","assetid":"3729557288863109072","amount":"1","classid":"3631599957","instanceid":"0","new_assetid":"3740816287932624686","new_contextid":"2"},{"appid":252490,"contextid":"2","assetid":"3729557288863109073","amount":"1","classid":"4481862621","instanceid":"0","new_assetid":"3740816287932624689","new_contextid":"2"}]}]}}
It's weird that this thing is happening on player to player trade, without any bots and codes. It only happens for rust, as far as i noticed myself.
I was wondering to get some "debug" items and make a tradeoffer whenever "missing items" error occurs while trying to send an offer with the requested items. Because they are in the inventory, but they are hidden till a new item pops up.