BibTeX does not have the right entry for preprints. This is a hack for producing the correct reference:
@Booklet{EasyChair:9368,
author = {Frank Vega},
title = {Sharp-P and the Birch and Swinnerton-Dyer Conjecture},
howpublished = {EasyChair Preprint no. 9368},
year = {EasyChair, 2022}}