yeah, unreal is fine for animations but you do have to know the workflow - so firstly there’s an option on import for combining meshes if you want to keep things separate in maya and then have them come in as one object. this can be useful for modular sets and things but personally i just like to keep one file per mesh as it makes it easier to identify things.
secondly with your skeletal mesh problems you need to understand what a skeletal mesh is trying to do. it was first used in the engine for rigged animations - ie a mesh applied to a skeleton of joints. That means you need to do the same set up for the rigid animation that you’re doing now, luckily for you though you dont have to make a joint per box and set up a rig - unreal will do it for you if you set up the scene correctly.
so the important thing to remember is that the whole animation needs to have a common root bone - in maya this can just be a locator i believe, and this is the pivot point of the model. then you can build your animation on top of that, with as many parent/child pieces as you want. when you import the fbx with animation unreal should pick up that it should be skeletal and ask you which skeleton you want to use - if none exists yet it will create one automatically. the advantage of this is that you can have multiple models sharing the same animations etc. but we dont often need that for fx type work.
its also worth remembering that some sorts of animation deformers and tools that work in maya might not export correctly into unreal - you might have to bake the keys on the cubes so that the animation is just on the mesh instead of the deformers.
let me know if you’re still struggling and i’ll put together a quick video for you, hope that helps!