How to reproduce:
1. Open the attached "1312520 repro" project
2. Connect the project to Perforce
3. Add and Submit the Assets, Packages, and ProjectSettings folders to Perforce
4. Open the Addressables Groups window from Window > Asset Management > Addressables > Groups
5. Click Create > Group > Blank (no schema)
6. In the pop-up agree to check out the AddressablesAssetSettings.asset file
7. Repeat the 5th step

Expected results: the pop-up doesn't appear again as the AddressablesAssetSettings.asset file is already checked out in Perforce
Actual results: the pop-up appears again even though the AddressablesAssetSettings.asset file is already checked out in Perforce

Reproducible with: 1.16.6, 1.17.6-preview (2018.4.32f1, 2019.4.23f1, 2020.3.0f1, 2021.1.0b12, 2021.2.0a8)
Not reproducible with: 1.10.0, 1.16.1 (2018.4.32f1, 2019.4.23f1, 2020.3.0f1, 2021.1.0b12, 2021.2.0a8)

Notes:
-The Group schema doesn't matter in the 5th step, the status of AddressablesAssetSettings.asset isn't checked either way