Why did IDM Change the URL Address from http to https and vice versa?

Question

i wonder why internet download manager (IDM) sometimes changed the url from HTTP to HTTPS and vice versa? even though that is incorect of course i mean because of that miscalculation when i download the URL Download (Like a game, app, software etc. from example i tried to download warcraft III frozen throne from apunkagames.com but because idm remove the "s" and it became http i cannot complete its download and error message pop up) so why does it do that? and how do i prevent it from doing it?