How to reproduce:
1. Open the user's attached project
2. Open Window -> Asset Management -> Addressables -> Settings
3. In the Inspector window, find the "MonoScript Bundle Naming Prefix" setting (under "Build")
4. Set "MonoScript Bundle Naming Prefix" to "Custom"
5. In the "MonoScript Bundle Custom Prefix" field, write "helloworld"
6. Go to Window -> Asset Management -> Addressables -> Groups
7. In the toolbar of the Addressables Groups window, select Build -> New Build -> Default Build Script
8. In the project folder, find the directory Library/com.unity.addressables/aa/OSX/StandaloneOSX (or Library/com.unity.addressables/aa/Windows/StandaloneWindows64)
9. Observe the filename of the MonoScript Bundle

Expected result: custom naming prefix appears in filename
Actual result: custom prefix doesn't appear in filename, hash appears instead, and is attached as a suffix rather than a prefix

Reproducible with: 1.18.2, 1.18.15 (2019.4.29f1, 2020.3.16f1, 2021.1.17f1, 2021.2.0b7, 2022.1.0a5)
Could not test with: 1.16.19 (relevant settings not found after downgrading)