After updating my wiki site to 1.41.0, MobileFrontend no longer load Mobile.css, instead it loads Minerva.css. Using Chrome's inspection tool, the loaded CSS has this URL:
https://www.tunguyentiengviet.com/load.php?lang=en&modules=site.styles&only=styles&skin=minerva
Adding mw.loader.using('mobile.site.styles') did not help.