KatMovieFix (originally emerging around 2017–2018 as a spin-off/alternative to KickassTorrents and other pirate platforms) was, for several years, one of the more popular websites. Unlike torrent sites that required a client and exposed your IP, KatMovieFix offered direct HTTP downloads and embedded streams.
Sites like Katmoviefix rarely operate on a single URL for years. They switch domains (e.g., from .com to .xyz, .cool, or .org) to avoid bans. The "Old" version users remember was likely hosted on a domain that has since been seized by authorities or abandoned. Searching for "Katmoviefix Old" is often a user's way of trying to bypass a blocked domain.