Partial classes being deleted on regeneration

[Relki]

I'm adding partial classes to the generated Context file. I've tried putting the partial class in the same folder as the generated class. I've tried putting it in a different folder, but adjacent. But, when I regenerate the designer code from the EF designer, it regenerates the generated code, but then deletes my custom partial context class. The only way I've been able to have the partial context class not be deleted, is to put it in the root of the project level. Then it doesn't get deleted by the code generator. Any clues as to what I'm doing wrong? Is this a bug?

Generate code deletes the AccountModelContext.Encrypted.cs file in both these scenarios.

But doesn't delete it in this scenario.

Generated code:

My Partial class for the same context;