So basically I have 2 tilemaps - one tilemap for non-solids and 1 tilemap contained in an Area2D for solids. The reason I made 2 tilemaps is because I have projectiles that I want to remove when they hit a wall, so I made a separate tilemap for walls that I put in an Area2D so the projectiles could detect collision with the walls. This works fine, the projectiles get removed once they hit a wall.
BUT, now when I try to make my character go towards a wall, he goes straight through. I've tried putting the tilemap outside of Area2D node, but it still won't resolve the collision. The tilemap has the exact same settings and masks/layers selected as the other tilemap. When I try to put a solid wall into the first tilemap, it works fine, and the character doesn't go through the wall. But when I do the same with the second tilemap, it doesn't work.