Why are videos that are 3 months old not being marked as viewed?

Question

YouTube

For example, there is a channel on which I watched a video for a long time and scrolling down the page, the videos are not marked as viewed. same theme in history.
Whether this is due to the browser or there is a limit on the settings, I don’t know.
Who knows the answer I will be glad to answer.

Answer 1

One of two things:
1) Either this is a youtube bug
2) Either this is the way it is intended, so that long-standing actions on the channel are cleaned up as unnecessary.

Answer 2

Perhaps your browsing history for such a period is cleared