Vertex Painting is not working on a large terrain

Hello…I have set up a vertex painting material and it works on a simple cube but when I try to paint on my terrain it doesn’t work …the paint brush doesn’t show up… Here is a video of the issue I am having… Thank you for your help.

Seems like you are panning the camera instead of painting.

Also the terrain has way too high a tiling which may prevent changes from being visible (even if it doesn’t look like you are painting).

Activate the debug mode on the top left and verify what colors show up / if you are indeed painting the verticis or not.