How to reproduce:
1. Open the attached project "AddressablesContentUpdate.zip"
2. In Addressables Groups window make a New Build (Build > New Build > Default Build Script)
3. Build And Run
4. In the Player window click on "Check for Catalog Update"
5. Click on "Check for new Content"
6. Click on "Load"

Expected result: Content is loaded
Actual result: Content is not loaded and errors are thrown in Debug Console

Reproducible with: 1.18.9 (2018.4.36f1, 2019.4.28f1, 2020.3.13f1, 2021.1.13f1, 2021.2.0b1)
Not reproducible with: 1.18.4 (2018.4.36f1, 2019.4.28f1, 2020.3.13f1, 2021.1.13f1, 2021.2.0b1)