SE Internship: online technical (2 DSA + SQL + 11 CS theory), passed, then rejected before HR final

Applied via LinkedIn and after few days got online technical interview with 2 coding (DSA), sql query and 11 computer science theory questions. Completed and after 2 days I got informed that I passed this round and HR scheduled last part of interview process for 30th December. Today I got rejection because they mention we chose another candidate. Very frivolous from company employers. Also site for interview candidates is very bad and got a lot of bugs.