Here’s an example of what I mean.
The animation is playing on the left. My player object already has a down and up animation looping as intended.
Hmm took a look at the animation, one thing I noticed is that the frames show up in the wrong order, is that intentional? If we take for example the frame animation you posted above, and number the frames from 1 to 6, they show up in the video in this order -> 1 3 4 6 2 5
I doubt this would fix the pivot issue, but maybe it can help make it more clear where the issue is?
Other than that, I can only assume something is misconfigured in Unity, and unless you show us how it is currently configured, I doubt anyone can offer more advice.