DataSmith import from 3dmax file animation breaks

Hi I have a pretty clean scene. Many objects over a fairly long time line 3000 frames. many linked to helpers. no groups, everything attached that can. I bring in the animation to the latest UE4 with max 2019 and most current data-smith. I put the animation widget in the scene, and have auto play checked. When I play the animation plays, close and open scene still plays ok. But if I open sequencer, and then close sequencer (leaving sequencer on frame 0) the scene breaks. Many objects flip. things stop working correctly, some things don’t play at all. Close and open scene and it is permanently broken. Been hoping in the last couple releases this would fix but still have the same problem.
What to? Thanks

Can we have that max scene to test it locally?

Thanks how should I send it to you?

send me a wetranfer at and we will have a look.