Fixed some issues

frontend/src/components/RandomVideoUpload.tsx

@@ -71,6 +71,7 @@ const RandomSignUpload: React.FC = () => {
             // check if the sign is different from the current one
             if (sign === null || sign.id !== response.id) {
                 setSign(response);
+                setUploadProgress(null);
                 // set the video url
                 setSignVideo(response.video_url);
             } else {