Reproduction steps:
1. Open the attached 'AddressablesSortOrder' project
2. Go to the 'Window -> Asset Management -> Addressables -> Groups'
3. Create a new Addressable Group 'New -> Packed Assets'
4. Drag and drop three number assets from the 'Assets\\AddressablesContent' folder to the 'Packed Assets'
5. 'File -> Save Project'
6. Observe the 'Packed Assets.asset' in the Finder, note that Assets are serialized in ascending order, same as in the Addressables window
7. Remove all Addresables Assets from the 'Packed Assets'
8. Drag and drop three number assets from the 'Assets\\AddressablesContent' folder to the 'Packed Assets'
9. 'File -> Save Project'
10. Observe the 'Packed Assets.asset' in the Finder

Expected result: Addresables Assets are serialized in the same order as they appear in the Addressables window
Actual result: Addresables Assets are serialized in descending order, in the Addressables window they appear in ascending order

Reproducible with: 1.18.19 (2019.4.36f1), 1.19.19 (2019.4.36f1, 2020.3.30f1, 2021.2.14f1, 2022.2.0b11, 2022.2.0a7)

Notes:
- This issue appears only the second and subsequent times the Addressables Assets are added
- Occasionally assets are serialized not in descending order but arbitrarily