ApplyAdditive Animation Node Issue - not moving

Hi, for this free asset
KC-135R Air Tanker (West)

there is a animation for rear and front wheels retraction. The animation, when viewed in editor is working correctly. As it can be seen here: [Wheel animation][1]

If I use ApplyAdditive Node in ABP

– and use Alpha as input, the wheel chassis main doors do not move at all and the wheel is glitching through, as seen here: [Corrupt door closing video][3]

Even if we make separate animation, which includes only these bones, the issue persists.

What we have tested, it might be caused, because the initial position and finishing position of that door are exactly the same. Additionally, to it, when we partially rotate the door in UE4 animation as new animation additive layer, there is some minor movement, but the animation is still not added correctly.

For me it looks like, the ApplyAdditive sees no difference on start and end of animation and thus multiplies (and not adds) the whole animation with zero – resulting zero changes.

For other animations - used exactly the same way, that do not start and end on same point, this does not occur.

Did anybody experience this please?
Or has idea how to solve the problem.
Many thanks