How to reproduce:
1. Open the users attached "TextureBug.zip" project
2. Build the assets (Window -> Asset Management -> Addressables -> Groups -> Build -> New build -> Default Build Script)
3. Check how many shaders are in the built bundles

Expected results: There are 3 built shaders
Actual results: The 3 shaders are duplicated across every bundle

Reproducible with: 1.16.13. 1.17.13 (2018.4.33f1, 2019.4.23f1, 2020.3.2f1, 2021.1.1f1, 2021.2.0a10)
Not reproducible with: 1.16.10 (2018.4.33f1, 2019.4.23f1, 2020.3.2f1)
Could not test with: 1.16.12 (Can't install this package version)

Note:
- In step 3 to check what was built in the bundles it is recommended to use this tool: https://github.com/faelenor/asset-bundle-analyzer
- Doesn't seem to reproduce with imported shaders