Double schema?...

My website's rankings fell down the gutter after installing a review plugin. Maybe because of it, or maybe because of the recent Google updates, please help me out.

My setup: Wordpress with RankMath, LocalBusiness schema. Review plugin adds its own LocalBusiness schema, matching the first one, but with ratings and reviews. Could this "double business" be an issue? No errors in GSC or any validation tools I tried.