How to reproduce:
1. Open the attached project “VSDebuggerBug.zip“
2. Set Visual Studio 2022 as External Script Editor (Edit → Preference → External Tools)
3. Open the “SampleScene” in Scenes
4. Open the “ExampleScript.cs” script in Assets
5. Enter the Play Mode
6. Press Window → “My Window”
7. Attach Unity Debugger to the Editor
8. Hover the cursor over the “MyWindow” custom window or try making any changes to it
9. Observe the editor and “Stats” window

Expected result: FPS doesn’t drop. There’s no lag in the editor
Actual result: FPS drops. There is a lag in the editor

Reproducible with: 2020.3.41f1, 2021.3.13f1, 2022.1.22f1, 2022.2.0b14, 2023.1.0a18

Reproducible on: Windows 10 Pro

Notes:
- Not reproducible with VS 2019
- Everything works as expected if “MyWindow” is turned off
- Also reproducible if the script is attached to unity without entering Play Mode

Workaround:
In Visual Studio:
1. Press Debug → Windows → Exception Settings
2. Add "UnityEngine.ExitGUIException" to the well-known exceptions in the Common Language Runtime Exceptions category (using the + button on the toolbar)
3. Uncheck it so that the debugger doesn't break on it