I had this happen a couple weeks ago. I found a UFC event (if I remember correctly it was Fight Night 156 Prelims) on another tracker and downloaded it. Since it was still not available here, I created a new torrent file and shared it here. A couple people downloaded it from me and another user was half-way through when it turned red in RuTorrent. I tried to stop and start it and then tried to re-download the torrent but it was gone and no longer showed in my profile's uploaded torrents. I checked the Latest Torrents section on the home page and there was a different release available, but mine was gone.
This has also happened a couple times in the past, in reverse. A new release becomes available on the home page. I download it and start to share. I check back a little while later and it is red in RuTorrent and the torrent has disappeared from the homepage.
The only thing I can assume is that someone with admin level privileges is deleting them. But if they are breaking some rule, why are no messages or warnings being sent out to those who are uploading or downloading these deleted releases? Just wondering...

You most likely made duplicate uploads of already released material. Search before upload and avoid uploading already uploaded material.

Also avoid uploading releases that contain advertisements added not original like PUNCH and CABBOWABBO releases for example. These are forbidden.

Thanks for the information. They may have been PUNCH releases. I never even noticed the extra advertisements.

Instead of removing ads they add one. So best avoid them.