Math assignment operators done in a numeric field don't return the expression result

How to reproduce:
1. Open the user's attached "repro UIToolkit" project
2. Open the "SampleScene" Scene
3. Select the "Test" GameObject in the Hierarchy
4. Enter "/=5" assignment operator in the "Test (Component) -> UI Toolkit -> X" numeric field in the Inspector

Expected result: "UI Toolkit -> X" field value is set to 1 (the division expression result)
Actual result: The expression result is 0 when a multiplication-related assignment operator is passed, or the addend if sum-related

Reproducible with: 2021.3.0f1, 2022.1.0b16, 2022.2.0a10
Couldn't test with: 2019.4.37f1, 2020.3.33f1 (the '=' symbol isn't writable in the numeric fields)

Note: The bug isn't reproducible with IMGUI fields with some versions. The Expected result can be observed in the not reproducible versions of case 1399184