Reproduction steps:
1. Open the user's attached project and SampleScene scene
2. In the Hierarchy window, select Canvas/Button
3. In the Inspector window, drag the Test (Script) component (the one that has the Proof field set to "Second") into PointerEnter event field
4. In the PointerEnter event, set Test/LogProof() as a function
5. Enter the Play mode
6. In the Game view, hover over the button and observe the Console window

Expected result: "Second" is logged
Actual result: "First" is logged

Reproducible with: 2018.4.32f1, 2019.4.20f1, 2020.3.0f1, 2021.1.0b9, 2021.2.0a7