Thanks for this report @davidkingham, this one is actually a known issue of sorts, in that it’s not clear that this should behave differently from how it currently does.
If the condition that activates the next step is met the button should read Next
If the condition that activates the next step is not met the button should read Done
Both are possible and won’t be determined until the step is submitted. “Next” was considered more open ended, i.e. better suited to deal with the two possibilities.