Hello, I’ve encountered this problem where an imported animations look a bit different. When I downloaded animations from Mixamo they were a bit different but playing with animation import settings I could fix it, now I made animation myself in blender and import settings doesn’t help. There are screenshots:
Well I figured it out myself, it was a dumb mistake. The problem was in the animation itself, though in Blender it look well when exported it was broken. When imported in Unity it had broken T-pose and the animation itself. So what I did to fix it is I created another animation where character is in T-pose (Or closer to it to let Unity easily define T-pose), I imported it and T-pose was set correctly in Unity and my sitting animation was also fixed.
I am having that issue with mixamo that you mentioned in the beginning, I don’t know anything about 3d modeling or animations so I don’t know what to do at all to fix this.