This problem is likely caused by an unstable connection. We therefore advise you to switch to 4G if you were using Wifi, or vice-versa. Please also check whether you have enough storage space to record the video pre-interview (around 50Mo).
If you do not have access to your image gallery or your camera, no video will be sent. You may check this in your accessibility settings.
If the problem remains, you can remove and reinstall the app and try again. You may take the interview over again using the same access code.