“quaeritur num mors malum sit.”
“the question is whether death is an evil.”
The translation makes sense to me, but my first translation would be “whether death is an evil is being questioned.” Now you might say it’s the same thing, but it seems to me that there is a difference and the latter is also possible, and I can imagine a context where it would be. For example, if a group of philosophers were discussing something, and someone asked what they were talking about, the translation I gave would make more sense, but the given translation seems to me to indicate that there is a certain construction in Latin here that I need to learn. Maybe this is just how Latin forms the “The question is whether…” construction, and the latter is not possible for whatever reason.
quaeritur doesn’t mean something is being questioned in the sense that doubt is being cast on it (as in “I question whether death is a bad thing—in fact I’d say it’s a good thing”). It means that something is being enquired into. So it’s a matter of the meaning of quaeritur. (Quaeritur quid “quaeritur” significet.)
What exactly is your point? In English, of course, there is a slight difference between something being “questioned”, “enquired into” or “the question” (or “investigated” etc., etc.). They can all serve as more or less accurate translations (i.e. approximations) of the Latin “quaeritur”, which however, to be exact, only means “quaeritur”. The different nuances of the English phrases don’t really tell us anything about the Latin.