Blender Animation only one rotation

Hi I hope someone can give ma an answer to my question.

I have created a cubelike object in Blender. After that I made an animation for rotating 90 degrees in each direction. (It’s not a normal cube, see picture).

Now I am trying to import the animation which works well. But now comes the turning point,
after one animation, it is resetting the object’s rotation to 0 again.
So do I really need a animation for one hole spinn around each axis ?
Or is there a way of spinning relativ to the current rotation ?

26942-example.png

I appreciate every help or idea.

Indeed PouletFrit is right.

But if you insist;

It sounds like you are using Legacy Animation system? This will always snap back at the end. Set it up as a Generic Rig and make sure to Not bake your rotations in Import tab.

For this to work the model must be animated with a bone based rig. A single, central Root bone should be fine.