How to reproduce:
1. Download and open the attached project 'Animation Stutter.zip'
2. Open Scene 'Assets/Test/test_scene'
3. Make sure to have Game View, Scene View, Inspector windows open
4. Open any animation from the 'Assets/Test/Attacks/DC' folder (e.g., 'DC_Air_D')
5. Click the Stats button in Game View
6. Open Profiler (Window > Analysis > Profiler)
7. Enter Play Mode
8. Observe framerate in the Statistics window
9. Observe Profiler data

Expected result: CPU Usage and Framerate is stable
Actual result: CPU Usage suddenly increases and Framerate drops before going back to normal

Reproducible with: 2019.4.15f1, 2020.1.16f1, 2020.2.0b14, 2021.1.0a8
Couldn't test with: 2018.4.28f1 (Couldn't downgrade)