How to reproduce:
1. Open the “IN-70366“ project
2. Open the “World“ Scene
3. Click on the “Whole Body“ GameObject in Character Controller > Sprite > Whole Body in the Hierarchy
4. Click the “Open Sprite Library Editor“ button in the Sprite Library Component
5. Click on “Idle“ under “Local“ Section
6. Reorder the sprites in any way
7. Save the Sprite Library Editor window
8. If saving is not possible, select another “Main Library“ asset
9. Observe the “Labels” Section in the Sprite Library Editor

Expected results: Reordering is saved and shows the reordered list after a reload
Actual results: Reordering is never saved and shows the initial order of the list

Reproducible in: 2023.2.14f1, 2023.3.0b10
Could not test in: 2021.3.36f1, 2022.3.21f1 (No Sprite Library Editor window and no reordering function for individual Sprites)

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Note: After saving once on one “Main Library“ asset, saving might get disabled, unless the same or another asset is selected