How to reproduce:
1. Open the attached “parameter.zip” project
2. Enter “SampleScene” Scene (Assets > Scenes)
3. Open “New Animator Controller” and enable any of the checkboxes of the bool in the Parameters tab
4. In the Hierarchy window, select “Cube” GameObject
5. In the Inspector window, observe the “Zzz” value

Expected result: Value is 2
Actual result: Value is 0

Reproducible with: 2021.3.32f1, 2022.2.13f1, 2023.1.20f1, 2023.2.0f1, 2023.3.0a14

Reproduced on: macOS 13.5.2 (Intel)
Not reproducible on: No other environment tested

Note: if reloading the script, then the value is correct