Bug with humanoid rigging

I created this post a while ago showing a player character doing some wierd crouching thing when using IK and humanoid rig:

https://forum.unity.com/threads/weirdness-with-inverse-kinematics.754973/

At first I thought this was an error on makehuman's part. But I decided to test if this also happens in other humanoid models. I created a player model similar to the one in unturned using blender. When I set the avatar rig to humanoid after importing it to unity, I noticed that when I clicked on the muscle settings tab, the player still does the same crouching thing.

I therefore believe this is an error on Unity's part, and not makehuman as it happens to any humanoid model regardless of if it was made in make human or not.

Could the unity devs please investigate this and try to find a fix?

 

Did you try IK with free models from the Asset Store, for example?

I've used IK for feet and hands and I haven't had this kind of behavior.

If you go to the Muscle & Settings sub-section in Inspector/Rig/Configure, character is supposed to be in a crouched position. Purpose of that Muscle & Settings is for tweaking (and testing) your skinning and movement range etc.
https://docs.unity3d.com/Manual/MuscleDefinitions.html

However, if you character is crouched in the Mapping section, it's another issue...

Have you set up characters to be used in a game in Unity earlier?

 

Huh, did not know that. However when in play mode he still does the crouching thing. How do I fix this?