animation – Blender to Unity weight painting doesn’t carry over nicely

How to get Blender weight painting to work smoothly in Unity?

Here’s my workflow:
-Do weight painting in Blender.
-Do animations in Blender.
-Export FBX.
-Import in Unity
-Set avatar to humanoid(bones are a perfect match)

But the animation doesn’t play as smoothly as in Blender and deformations do not stretch correctly.

In Unity:

enter image description here

In Blender:

enter image description here

The animations work correctly overall, just doesn’t in some parts such as the knee.