How to reproduce:
1. Open the user’s attached “CanvasTest.zip” project
2. Open “TestPrefab” Prefab in the prefab mode
3. In the Inspector window, add the “Canvas” Component and press the “Save” button
4. Observe the “Sorting Layer”, “Sorting Layer ID,” and “Sorting Layer Name” fields

Expected result: “Sorting Layer” is “TestLayer1”, “Sorting Layer ID” is “-387114033” and “Sorting Layer Name” is “TestLayer1”
Actual result: “Sorting Layer” is “Default”, “Sorting Layer ID” 0, and “Sorting Layer Name” is “<unknown layer>”

Reproducible with: 2021.3.21f1, 2021.3.34f1, 2022.3.19f1, 2023.2.8f1, 2023.3.0b5
Not reproducible with: 2021.3.20f1

Reproduced on: macOS 14.2.1 (Intel)
Not reproducible on: No other environment tested

Note: sometimes it’s needed to wait a bit for fields to update