Bug Animation rigging broken in 2022.2 and above

The rig builder component breaks the character's animations. This is a very simple scene, with a single 2D blend tree in the animation controller.

This thread looks like the same exact issue: https://forum.unity.com/threads/rig-builder-destorys-humanoid-rig-animation.1290008/

I try to stay up to date with the latest alpha/beta releases, so I first noticed this in 2022.2.0a13. I am currently stuck on 2022.2.0a10, the last working version I know of. Just today I tried 2023.1.0a4, but no success.

My guess is it's something outside of the animation rigging package, because I am using animation rigging v1.2.0 (the latest version) in 2022.2.0a10 no problem.

The thread I linked to above mentions bug IN-4468 was opened up, but I can't find any details.

 

The issue seems only there while blending. If the blend tree is at min or max, it animates fine.
If I put the blend setting in the middle and toggle the Rig Builder on/off, my character pops up and down through the floor. You can turn off Apply Root Motion and it still happens. (using 2022.2.0b3)

 

Yes, I am observing the same thing too.