IK preview looks jerky in UMotion, but smooth in Unity Timeline

Hi,

I'm editing a motion using IK in UMotion Pro. While working on a jump animation, I noticed that the knees "snap" or move abruptly when they are fully extended. I spent a lot of time trying to make it look smooth in the editor, but eventually gave up because it never looked quite right.

However, when I exported the animation and played it in Unity's Timeline, the motion looked smooth and properly interpolated—much better than what I saw in UMotion's preview.

Is there any way to make the IK preview inside UMotion more closely match how the animation will look in Unity? I’d really like to edit with more confidence, seeing what the final result will actually be.

Are there any settings or modes I should enable for this?

Thanks in advance!

(*This message was written with the help of ChatGPT to assist with translation.*)