I have set my phone to switch between light and dark mode on schedule. Everytime it does so, Firefox doesn't theme refresh correctly. Usually, the search bar will be on the old theme and I'll need to close Firefox as an active app and restart it to refresh correctly. This also means websites looking for theme refresh signals from the browser do not pick it up correctly and thus the browsing experience is visually jarring. This issue has been around for more than a year. Reinstalling Firefox hasn't helped. This is a bug in the browser code and can be reproduced on my Android tablet as well.