Welcome to the forum!
I realize that this is frustrating, and have been allowed to post this topic to explain why this happens: Why an accepted Wayspot may not be used in Pokemon Go (S2 cells and Pokemon Go)
For a visual, you can see that your Garry point co-op garden is in the same cell as the Pokestop Richmond Street Park Playground
so it is not eligible to be a Pokestop or gym. It could potentially be used as a Power Spot at some point.