I can't paint Palms using the Paint tool.

I can't seem to paint Palms onto my terrain using the add trees tool. I can get every other tree, bush, grass to work, but not the palms. I even found another palm asset to see if those would work, and they didn't. I can drag palm tree onto the terrain, but when trying to cover a map, that's not really what I want to be doing. lol I am new to Unity, so maybe I'm missing a setting that's palm tree specific? Can anyone help me, please? (thank you in advance!)

I have tried the mass place trees, that doesn't work with the palms either.