@kezz I moved your post into a separate thread for possible “troubelshooting”.
Could you describe what exactly is not working? (do you get an error message? do you see autofill suggestions? do you see them, but “fill” doesn’t do anything…?!)
Latest Bitwarden would be which version right now on your device?
BTW, you are using the BW mobile app? Or are you using the browser extension on Vivaldi?
Honestly, I don’t think there is anything Vivaldi-specific in there – and it did work for you until recently as you wrote – but anyway, you could have a look into this guide as well to check some basics and beyond: [Short Guide / Tips] Autofill on Android (and: maybe just toggle BW autofill on your device – can help also sometimes)