I know this post is quite old, but I’ll leave it here for people on the internet that may stumble with this post.
UE5 does not support animated tiles within a tilemap by default, you can however place them manually as flipbooks, like the comment above suggested, however that is quite tedious to do one by one by hand.
I made this plugin to work alonside the Tiled map editor (which has quite more features to work with tile maps and tile sets) and let’s you import those maps into UE5. And in addition it supports animated tiles out of the box without having to do manual flipbooks.
You can check it out here: https://www.fab.com/listings/5906c3e1-6ca6-48b3-9694-57fbb0c08037