Exactly. The term "stable" in connection with software has the same problems of "free"; without understanding the context, it can be interpreted wrongly. "stable" type of distributions are meant to be "unchanging" in the sense of feature freeze. That off course depends on the distro or software in general how far this goes. Archlinux is "unstable" in the sense it is ever changing and adapting new technologies by breaking compatibility; something Debian does not.

I know, I was referring to the heading implying otherwise:

It turned out to be more stable than I expected.

Depends on your definition of "reliable" 😉