Same Post Shows Multiple Times In Category Archives

OK, have an interesting situation, not really a problem, but, slightly annoying. Have hunted around, but, can’t seem to to come across the answer.

Essentially, for some categories, I have “children”, just to keep it all together. Typically, when I use the parent, I often use at least one of the children. Because of this, when you enter the category for the parent, the same post can show 2, 3, even 4 times.

For instance, my global warming category (https://www.thepiratescove.us/?cat=56) notice that they often show up multiple times, due to the children. (yeah, you might not agree with my POV, but, that’s an argument for another day.)

Is there any way to stop that? Could it have anything to do with most of the main categories showing up as a number, and the children showing up as a name? I originally used numbers, then switched.