Well then without seeing the actual page it's not going to be possible to tell you how to do it. 95/100 times IDM works!
Using coccoc (https://coccoc.com/). This is just like Chrome in Vietnamese version, most Vietnamese using this instead of Chrome. Because many function including download videos. Please give it a try.
Bro Could you please post this two? https://www.mzed.com/courses/deadfall-script-to-screen https://www.mzed.com/courses/advanced-editing-with-davinci-resolve
You can try FireFox browser with Video DownloadHelper https://addons.mozilla.org/firefox/addon/video-downloadhelper/. To have full power and options you need to install a companion app and pay a small fee for registration. PS. I'm not affiliated in anyway with them, just can say that it works pretty well in most of the cases.
Hey @fatjo you still got that MZed subscription. Maybe you can try Jdownloader to download from there. If that works can you please upload this course - https://www.mzed.com/courses/advanced-editing-with-davinci-resolve