Snapshots and releases being replaced

Hey guys, so when a new release or snapshot releases (example: 1.16 to 1.17) my previous one gets removed and replaced and I sometimes can't get it back. When Snapshot 1.17.1-pre1 released, my Snapshot 1.17 was removed entirely and replaced. There needs to be some way to turn this off. I haven't seen any ways yet. I want to be able to keep my old versions and use them later when I have to.