This is probably due to the proximity rules and Pokemon Go that uses S2 Cells.
More details Why an accepted Wayspot may not be used in Pokemon Go (S2 cells and Pokemon Go)
Just an extra note, if by this comment you mean that you nominated the “Swings”, “Slide”, “Climbing Frame” etc all as different nominations then this is against criteria and everything apart from the 1st one should have been rejected. A “Playground” should be 1 nominations.
If there are other parts of the park such as Basketball court, picnic area then these can be nominated separately.
Good luck
Hi
This is a map of the park, the green boxes are the level 17 cells ( ignore the white lines they are just about the imagery. You can only have 1 pokestop per each level 17 cell. This map is not up to date so it doesn’t show any new wayspots added in past 3 months.
Unfortunately the dragon is in the same cell as the Vichy Community Park pokestop then the dragon won’t appear in game.