Beno Majer - Who He?

[Vox Humana]

Being an avid seeker-out of anything I don't have to pay for, I keep an eye on IMSLP and noticed the recent edition of some organ sonatas by Beno Majer, who I must admit was entirely new to me. Despite never having heard of him, this sonata struck me as ever so familiar and after a few moments the penny dropped: it's the opening movement of one of Haydn's early piano sonatas. Does anyone happen to know what has gone on here? Is it a case of simple misattribution or downright plagiarism? Perhaps a check of Majer's other sonatas would be in order!