I use free software called Any Video Converter (AVC) to download. It's as easy as dragging the video file name off the rumble page onto the AVC main screen. Your download progress will be shown and once completed you will find it in a sub folder under your Videos folder.
(You can convert them also to another file format if you want but it's not necessary.)
This is the link to get information about and download AVC -
https://www.any-video-converter.com/home/