It depends on how the file is shared.
6-digit Key Transfer or To device Directly
You cannot continue to upload or download paused files because of directly transferring files in real time.
You can continue to upload or download paused files because Share-Link transfer files to the server and store files for a period of time. Click 'Resume' button in History menu. However, if the link is not fully uploaded or the link has expired, you cannot resume to download it.