Reproduction steps:
1. Open the attached “repro_IN-88612“ project
2. Open the “Assets/Test.unity“ Scene
3. Open the Task Management window (“Tools → Task Management“)
4. In the top-right, press the three dots button and select “New Task“
5. On the right part of the whole window, move the black slider from “Text“ to “Tasks“
6. In the “Sub Tasks“ section, keep pressing the '+' symbol until the whole “Sub Tasks“ area is filled, then press one more time
7. Observe the Console

Expected result: No errors appear
Actual result: The Editor hangs a bit on the “TaskManagerWindow.MouseUp“ window and then a lot of “UnityEngine.UIElements“ errors appear

Reproducible with: 2023.3.0a2, 6000.0.27f1, 6000.1.0a4
Not reproducible with: 2022.3.52f1, 2023.2.0a23
Couldn’t test with: 2021.3.46f1 - Not able to downgrade due to compilation errors

Reproducible on: Windows 10 (22H2), Windows 11 (10.0.22631) (user’s)
Not reproducible on: No other environments tested

Note: On the FAV version, the “StackOverflowException“ error appears and the whole Editor becomes frozen