Link & Page Categories cross-update (bug?)

I had a Page category named “Community”.

I created a Link category named “Community”, but later edited it to “Community Links”.

And was surprised to find that the Page category had updated itself to the new name of the Links category.

I’ve disabled all Plugins, and yet, when I go to Edit either category (via the actual Edit page), the other is updated too.

Is this a bug? Certainly not a major issue, but it’s quirky.