Animation Loop ends in jitter.

I’ve been attempting to figure this out through experimentation for about 2 days. But I created a model in blender, created a looping animation, and imported it as an fbx in Unity with the rig set to generic (it’s a very low poly model that doesn’t have enough bones for the humanoid rig), but no matter what I do, I can’t get it to loop smoothly.

I created a VERY simple animation…

Frame 1: Left arm down, Right arm up
Frame 10: Left arm up, Right arm down
Frame 20: Copy and pasted from Frame 1

Looking at the preview, the animation looks EXACTLY how I expect it to. With looping on or off, it doesn’t matter because I made the first and last frame exactly the same. But when in the game I set the animation speed to 0.5 and I notice at the end of the animation both arms jut noticeably into the first frame’s position.

Is there something I’m doing wrong when making the animation? Or is there some other bug causing this? I can’t be the first person to notice this.

Figured it out based on the comments given. Turns out I was adding the animations to the controller wrong. I was creating a new empty state and filling in the animation, but the better way to do it is to drag the animation from the project into the animator. This gave me sliders to mess with the time it took to blend two animations together.