I have some communities on my small instance that I will never browse, I want to remove them to free up space and not pull useless data (to my one other user and I). I click "Remove" on the community and then I click "Purge" and the community is removed and purged, but a few seconds later the community is back with different content.

I know I can block the communities to stop them from showing up on my "All" feed, but I have a small instance and don't want that data sitting around if nobody will ever look at it, as well as limit the small amount of unnecessary additional strain it may put on other instances. What am I doing wrong?