imported anim is not moving when bone name has bracket

unreal 5.3.2; importing fbx; bone name has bracket
as long as the three factors’ there, the animation is not moving at all
I’ve tested multiple version of blender and fbx, it doesn’t matter
I’ve seen similar case in the forum, the answer is: use gltf
because gltf auto replaces brackets with underline
I believe the bug only happenes with certain version of unreal engine cuz my pineline was doing fine before, maybe it’s 5.3
I don’t see the bug’s fixed in unreal 5.4’s release note, so I guess the bug’s introduced in 5.3 and still exists in 5.4

Do you have a sample you could share with us?

This bug can be easily reproduced.
I create a simple anim in blender and export 2 fbx files.
bracket-test.blend (883.6 KB)
The only difference is a “(” in leaf bone.
test-bracket.fbx (37.9 KB)
test-no-bracket.fbx (37.9 KB)
After imported into UE, the anim of skeleton with “(” is not moving, while the other one is fine.