How to reproduce:
1. Open the “IN-96493_AppUI Test“ project
2. Open the “SampleScene”
3. In the Hierarchy window select “UIDocument”
4. In the Inspector window expand the Event System Component and click “Add Default Input Modules”
5. Enter Play mode
6. Click the “Test Me” button
7. In the popup click “OK”
8. Click the “Test Me” button again

Expected result: a popup appears
Actual result: nothing happens

Reproducible with: 2023.1.0a24, 6000.0.41f1, 6000.1.0b9, 6000.2.0a5
Not reproducible in: 2021.3.0f1, 2021.3.49f1, 2022.3.0f1, 2022.3.60f1
Could not test with: 2022.1.0a1, 2023.1.0a22 (Compilation errors due to older packages not having methods used in the project)
Fixed in: 6000.0.42f1, 6000.1.0b10, 6000.2.0a6

Reproducible on: macOS 15.3.1 (M1 Max), Windows 11 (by user)
Not reproducible on: no other environments tested

Note: In 6000.2.0a5 an error is thrown: “Recursively dispatching event UnityEngine.UIElements.PointerMoveEvent from another event UnityEngine.UIElements.PointerMoveEvent (depth = 484)” even with the Event System Component disabled, causing freezes.