Bug Custom locale selectors are Empty on project reload

Pretty much the thread title - I have two Locale Selectors I'd like to have run before the default ones, the RegionLocaleSelector and the StageLocaleSelector. I can add them to the list as follows:



When I add them both to the list and move them to the top, I get the following errors in the console:



However, it appears to work, because when I run our project in the editor, I am able to see print statements from those locale selectors, and they select the locale properly:



As well, once I close Unity, the LocalizationSettings file appears to have saved correctly, since my new LocaleSelectors appear in the Git diff of the file:



However, once I load the project up again, I see this in the Locale Selectors, and I get NullReferenceExceptions trying to run the project through the editor.



Am I missing something here, or is this a bug?

 

We are on 2019.3.3f1 with localization at 8.1 and addressables at 1.15.1. This workaround fixed for us - thank you!