Root unrecognized - Pelvis locked on custom rig - Messed up animations

Hey everyone.
Been scouting the web for days looking for answers to this problem I’m having with importing my custom rig made in Max to UE4. No relevant matches…

My problem is simple:

I have a custom rig setup made in 3dsmax. Once imported to UE, the Pelvis bone is being automatically recognized as the Root. Or something along those lines…
This basically messes up all the animations.
The Pelvis is locked in place and not a single animation looks correct.

I tried checking all the root motion options in attempts to fix it, but nothing worked.
Played around with different Export/Import settings…
I also tried using a tool called FBXRootAnimationFixUp but that didn’t work either. Apparently the issue I have is very different.
I tried every trick I personally know to try and get this rig to work… no success so far.

I suspect there’s a hierarchy issue with that rig, but I hoped UE could handle it just as Unity did.

This rig might be a little funky, and I haven’t made it personally, but I hope there is a workaround that would save me from redoing over 100 animations for this specific character.
It’s also worth mentioning that I just recently got into UE after working mostly with Unity, so I may have overlooked something very simple. Hope so at least…

Okay, solved it.
And this leads to one huge question.

Why can’t Unreal import splines/curves from a 3D package such as 3D Studio Max?
The most simple thing ever. (it’s not the FBX since the spline data can be saved to it easily, but it’s not converted to dummies or bones for some reason)

Those splines controlled the pelvis movement. On import to UE, they were eliminated completely and thus nullifying all pelvis movement.

Once I converted those splines to mesh, UE managed to recognize them.

Hi, I know this question is both resolved and roughly 1 year old, but I’m facing the same issue with Blender to UE4.

Could you please elaborate on how to convert splines to mesh?

Is this done through 3D software rather than UE4. If so, how? Is it the armature that has to be converted to mesh?

To be specific, I’m using the armature that the Mannequin uses, rather than a custom one.