Gravity stops working when there are 2 or more Animation Layers in the Animator and the "Apply Root Motion" option is enabled

Reproduction steps:
1. Open the attached “IN-55995 Gravity Weight Bug with Multiple Anim Layers.zip“ project
2. Open the “SampleScene”
3. Enter Play mode

Expected result: The “Square” GameObject falls downwards quickly
Actual result: The “Square” GameObject is not moving

Reproducible with: 2021.3.31f1, 2022.3.11f1, 2023.1.17f1, 2023.2.0b14, 2023.3.0a10

Reproduced on: Windows 11 Pro (22H2)
Not reproduced on: No other environment tested

Notes:

• Reproducible in the Player
• Reproducible in a new project
• Reproducible with both “Rigidbody” and “Rigidbody 2D” components (one of these is required to be present on the GameObject for gravity to work)
• The issue is most likely caused by the Animator.gravityWeight variable being set to 0 in the Unity Editor’s source code when more than 1 Animation Layer is present in the Animator (look for the link to the discussion with developers in the internal comments for more information)