Same problem here. I got the last Webview Update at 2022-01-19. Since Friday (2022-02-11) my App is in Dark Mode. Delete an Reinstall: everything is fine, but after closing and reopening: App is in Dark Mode.
Thanks to YoeriNijs with body.dark my App opens light Mode.
Edit: when opening and Splashscreen dissapears, for a short moment App starts in dark Mode, and then switch to light Mode