How authentic is the Hadith: "O Allah, Gatherer of people on a Day concerning which there is no doubt, gather me with my lost item," when something is lost?

Al-Shawkani mentioned in "Fath al-Qadeer" a Marfu' Hadith of the Prophet, peace and blessings be upon him, with a صيغة التمريض (a form indicating weakness of narration), narrated from Ja'far al-Khuldi, that whoever recites the verse: {Our Lord, surely You are the Gatherer of mankind on a Day about which there is no doubt. Indeed, Allah does not fail in His promise} (Aal-Imran: 9), and then says: "O Gatherer of mankind on a Day about which there is no doubt, gather between me and my property, for You are over all things competent," then Allah will return to him what he has lost.

This supplication has been attributed to Al-Muzayyin Al-Kabeer, one of the Sufis, who taught it to Ja'far Al-Khuldi.

Al-Nawawi mentioned in his "Bustan" that he tried this supplication and found it beneficial in returning lost items, and his Shaykh Abu al-Baqa' taught it to him.