My app just starting do this too. I think there must have been a fix in Android WebView to actually make it dark when specified. The next version of my app has all the dark mode logic removed until we fully support dark mode.
You should be able to just remove the prefers-color-scheme: dark media queries in your variables.css and then in your public/index.html change the following:
// Change this
<meta name="color-scheme" content="light dark" />
// to
<meta name="color-scheme" content="light" />