It personally intrigues me that this UFO hype - started just around the time when jets became operational in the USA - and a lot of German stuff .e.g. The Horton GO (more or less unknown features till then) came up - right to an F-117 and present unknown prototypes zooming around.
Maybe the "hype", what ever you mean by that, but recent reports go back over a century;
The Real Story Behind The 1897 Aurora Incident: When A UFO Destroyed A Windmill
And there are reports of sightings going back towards dawn of civilization, thousands of years ago.
As for "Horton GO", I think you mean Horten Ho229;
None of the V3 version were ever completed and flown, in Germany or the USA, so doubtful that aircraft could have generated any UFO/UAP sightings.
...
In April 1945, George Patton’s Third Army found four steel-and-wood Horten prototypes; a Horten glider and the Ho 229 V3, which was undergoing final assembly, were captured. Of three airframes, the V3 was nearest to completion, and was shipped to the United States for evaluation.
[11] Along the way, the Ho 229 spent a brief time at
RAE Farnborough in the UK, during which it was evaluated as to whether British jet engines could be installed, but the mountings were found to be incompatible with the early British turbojets,
[15] which used larger-diameter
centrifugal compressors as opposed to the slimmer
axial-flow turbojets the Germans had developed. The Americans were just starting to create their own axial-compressor turbojets before the conflict's end, such as the
Westinghouse J30, with a thrust level only approaching the BMW 003A's full output. It is uncertain if the aircraft's original Junkers-supplied engines were ever ran, although the American evaluation team at one point had the intention of flying it.
[11]
...
en.wikipedia.org
.....
FWIW, there was a similar aircraft, that never got beyond drawings stage;
Gotha Go P.60
en.wikipedia.org
www.shrm.org
