Weird bug on "Media created date"

I ran into a weird bug. Some files I download show date media created 01.01.1970 02:00.
If I use remove K-lite and install another (CCCP) it shows real date when I downloaded them.
Currently I’m using Mega pack and I have tried all different K-Lite codec packs, still shows downloaded date 01.01.1970 02:00.
Is there a way to show real downloaded date?

The codec pack should not have any effect on the dates shown by Explorer. That specific date corresponds to a timestamp value of 0. Some people intentionally set this value to hide the real creation date. That would explain why only certain file have the problem.

Or does the date of an already downloaded file change?

Another topic with same problem:
https://codecs.forumotion.net/t2041-windows-10-mega-pack-1136-wrong-mkv-file-creation-date