The short answer
AARO's Historical Record Report, Volume I, released March 8, 2024, reviewed US government UAP history from 1945 to October 2023. It found no evidence that any sighting was extraterrestrial technology, or of any program reverse-engineering it.
The All-domain Anomaly Resolution Office (AARO) is the Defense Department office responsible for UAP. Its "Report on the Historical Record of U.S. Government Involvement with Unidentified Anomalous Phenomena (UAP), Volume I" is dated February 2024. It was released on March 8, 2024, together with a statement from Pentagon Press Secretary Maj. Gen. Pat Ryder. The unclassified report runs 63 pages and covers the period from 1945 through October 2023.
Its central finding reads: "AARO found no evidence that any USG investigation, academic-sponsored research, or official review panel has confirmed that any sighting of a UAP represented extraterrestrial technology." It also found no empirical evidence that the government or private companies had been reverse-engineering alien technology. It concluded that most sightings were ordinary objects that had been misidentified, such as drones, weather balloons, spy planes, satellites, rockets and planets.
The report responded directly to claims made publicly in 2023. AARO assessed that "the inaccurate claim that the USG is reverse-engineering extraterrestrial technology and is hiding it from Congress is, in large part, the result of circular reporting from a group of individuals who believe this to be the case, despite the lack of any evidence." It also reviewed older studies, noting that the 1953 Robertson Panel had discussed "the complete lack of the recovery of any 'hardware'" from unexplained sightings.
The strangest section covers KONA BLUE. Interviewees told AARO it was "a sensitive DHS compartment to cover up the retrieval and exploitation of 'non-human biologics.'" AARO found it was only a proposal. After the DIA cancelled its AAWSAP/AATIP program, supporters pitched the Department of Homeland Security on a new program. It "would restart UAP investigations, paranormal research (including alleged 'human consciousness anomalies') and reverse-engineer any recovered off-world spacecraft that they hoped to acquire." DHS leadership turned it down.