Neutral term for "broken" in software

Known issue.

As an example of fairly standard usage in the software and technology sectors, a program or system will be described as having a number of known issues. These will typically by prioritised and addressed in a planned way. However, areas of a product that are not affected, can continue to be used without any issue.

Examples of common usage abound, e.g.: https://success.salesforce.com/issues_about

I'd describe that software as buggy. As a software developer, we often encounter buggy code/software/etc. It usually works just fine except for a few use cases. In my experience this is common parlance among developers.

The website works great, but for some reason you can't login if your e-mail address has more than 20 characters. It's a little buggy.

Of course buggy could also mean the application is hopelessly broken, so adding an adjective to clarify the level of bugginess might be worthwhile.

You might call this a euphemism, but I demo "buggy" software to managers and stakeholders all the time ("please don't click that button!"). I would never demo "broken" software... even if parts of the software would be considered broken. That appears to get at the heart of what the original question is asking.