Nvidia cards do work with Unreal Engine. If you had a card with insufficient VRAM, that might be the reason that it didn’t work for you if you’re spaking from your personal experience.
Additionally, due to better ray tracing performance, Nvidia cards are in fact preferred over AMD cards in projects that utilize that feature, plus there are other benefits in gaming and game development. This shouldn’t be interpreted as “AMD cards are not ideal for Unreal”, there are no issues with them as well.
You should not spread this false claim in other topics too, like this one. Users who see them in the future might be mislead into believing that.