Board Game Arena

To my understanding, on resources for two players a person may place multiple people on a resource space but only one player may put people on a specific resource space. I've seen my opponent put multiple people on Clay but for some reason every time I try to put a second person on wood it tells me "This place is no longer available." Sorry if this is something that is overly simple but could someone point out what I'm not understanding.

Once you have played people (one or more meeple) on a space, you can’t play a second time on this space.

I figured it out, I wasn't aware that I place multiple people when I place people on a space.