Working with the Animation Editor with a scene open has massive slow downs

[carbonated-peter]

• If I open the Animation Editor with a new empty scene, everything works fast and normal.
• If I have the Animation Editor open with a full scene, performance drops to 1-5 frames per second.
• Any of our scenes drop performance in BOTH the Animation Editor and the regular editor.
• Even with a small scene with only a handful of assets will reduce performance considerably.
• The only way I can use the Animation Editor is to have an empty scene which is not ideal. Sometimes I have a character in a level for testing while working on animations. That's currently impossible.
• In the Animation Editor I have a character and our animgraph open.
• This was never an issue in Lumberyard, seems new in O3DE.

Empty scene: Animation Editor 35 fps, Editor = 60 fps
Empty scene + 5 prefabs: Animation Editor 20 fps, Editor = 21 fps
Empty scene + 10 prefabs: Animation Editor 12 fps, Editor = 15 fps
Full scene + hundreds prefabs: Animation Editor 1-5 fps, Editor = 1-5 fps

Found in Branch
https://github.com/carbonated-dev/o3de
Commit ID from o3de/o3de Repository
custom engine version 2310.2

Desktop/Device:
Device: [PC]
OS: [Windows]
Version [10]
CPU [Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz, 3501 Mhz, 6 Core(s), 12 Logical Processor(s)]
GPU [NVIDIA GeForce RTX 3090]
Memory [32GB]