How to reproduce:
1. Open the “SplineAnimateBug“ project
2. Open the “SampleScene“
3. Open the “Cube“ GameObject in the Inspector
4. Toggle off the Play On Awake property in the Spline Animate component
5. Enter the Play Mode

Expected result: The “Cube“ GameObject starts spinning because the SplineAnimateTest.Start() is calling Play().
Actual result: The “Cube“ GameObject does not spin (seems to be related to script execution order)

Reproducible with: 2.5.1 (2021.3.37f1), 2.5.2 (2021.3.37f1, 2022.3.26f1, 2023.2.19f1, 6000.0.0b16)

Reproducible on: macOS 13.5.2 (Intel), Windows 10 Pro
Not reproducible on: No other environments tested

Workaround: Moving the “SpliteAnimateTest.cs“ below the Default Time slot in the “Edit > Project Settings > Script Execution Order“