Internet Download Manager Open Folder issue in certain cases

I've reported this issue before, today I dug a little deeper and I think I found the problem.

Basically, what usually happens is when selecting Open Folder in the IDM completed downloads list, the folder opens in DO showing the file selected. If there is a DO window already open, it shows the file in the same window.

In certain cases, it opens another DO window where the file is but not showing the file. Wait and another DO window opens showing the selected file.

This only appears to happen if the selected file in IDM is either an executable or mp4. I haven't got a downloaded mkv video to check that format.

From what we know so far, it's something IDM is doing:

But it may also relate to this issue which just came up (hasn't been fully investigated yet):

I forgot to add that if the selected file in IDM is a zip, rar, jpg, png, it opens DO correctly and instantly.