There isn't anywhere near enough detail here to work out if what you're describing is a Django problem, or a problem with your own codebase.
A valid test report gives the triager enough data to reproduce your problem on their own. This report has a stack trace, and a vague description that says you've written your own authentication backend.
Please reopen if you can provide enough detail to reproduce the problem. This means a detailed set of instructions, or a sample project (a *minimal* sample project) that exhibits the problem. Don't just dump your entire codebase on our lap -- do some pruning and cut out anything that isn't *directly* related to the problem at hand.