How to reproduce:
1. Open the “MultiplayerRTS“ project
2. Open the “Main” scene
3. In the Game view window enable the “Rendering Statistics” window (“Stats” button)
4. Enter Play Mode and observe the “FPS” field in the “Rendering Statistics” window for 3-5 seconds
5. Open the “ProBuilder” window (Tools > ProBuilder > ProBuilder Window) and observe the “FPS” field in the “Rendering Statistics” window for 3-5 seconds

Expected result: performance does not decrease and stays at about 600 FPS when the “ProBuilder” window is opened
Actual result: performance decreases by 100-300 FPS when the “ProBuilder” window is opened

Reproduced with: 5.0.1, 5.1.0 (2021.3.28f1, 2022.3.4f1, 2023.1.3f1, 2023.2.0a22)

Reproduced on: Windows 10 (by reporter), Windows 11

Notes:
1. For the 2023.2 stream a separate project has been provided where scripting errors have been fixed - “MultiplayerRTS_2023.2“
2. Depending on the Editor version the amount of performance that is decreased varies