Bug Animatior layer options cannot be changed

Fedora 30 (5.1.12-300.fc30.x86_64 #1 SMP Wed Jun 19 15:19:49 UTC 2019)
Unity 2019.2.5f1 Personal.

Whenever I try to change an Animator layer option that requires another pop up (Mask and Blending) the option window closes before I have a chance to change it.

 

I found a temporary fix by adding the below to my script.
It just manually loads the AnimationController and AvatarMask Assets and sets them.

Code (CSharp):

1. AnimatorController controller = (AnimatorController) Resources.Load ("PersonAnimationController");
2. AnimatorControllerLayer[] layers = controller.layers;
3. layers[0].avatarMask = (AvatarMask) Resources.Load ("MaskBody");
4. layers[1].avatarMask = (AvatarMask) Resources.Load ("MaskRightArm");
5. layers[2].avatarMask = (AvatarMask) Resources.Load ("MaskLeftArm");
6. controller.layers = layers;

 

I can confirm that. The enum picking for a pop-up doesn't work on Linux.