Here's a more useful link:
https://youtu.be/uYaPF5wZNEo?t=1h34s
Hi,
some parts of the piece sounded familiar to me. At first, as others stated, too, I thought of a transcription e.g. by Stradal, slightly varied, of the Brandenburg Concerto Nr. 3, G major.
https://www.youtube.com/watch?v=jPNbuOklgHYhttps://javanese.imslp.info/files/imglnks/usimg/1/1b/IMSLP25251-PMLP05337-Bach_-_Stradal_-_Brandenburg_No.3.pdf( There are e-minor parts in it, too, but one could refer to the beginning, too, I think. )
But I thought further, back into the past times, when long forgotten but super films were made.. .

Please listen to the questionable piece which is in my quote of mikeowski above, again, but start from
exactly 1:01:00 ...
and then... listen to this one, from ca. 1:08 or from ca. 2:05:
https://www.youtube.com/watch?v=yTpjlvFWvi0So, may be a modern composition, disguised as an "old" one?

Please note, that on this list,
https://www.halidon.it/musica-c1-artisti_vari_il_pianoforte_the_best_of_piano-g3318.htmlan "anonymus-sonata" isn't mentioned ( but 4 numbers seem to be missing, too, perhaps movements (?), according to the counting ). ( And note that the 1st Liszt-Concert isn't in "IN MI BEMOLLE MINORE", but should be in "mi bemolle MAGGIORE". )
So, may be, the "anonymus sonata" could have been a Youtuber's joke.

Or, someone will find out more about it.
Good night, everyone, and greetings from: 8_octaves!