Character falling through floor, but vehicle doesn’t

Hi there,

I just datasmithed some meshes into the ArchViz template,
and then added features “Vehicle, Advanced” and “Third Person”
and added their BPs to the level.

When playing, the car stays on top of the geometry fine, but the third person character immediately falls through the floor. (On the same mesh.)

Anyone got an idea why, and what I could further into further to solve that?

(The meshes got imported as Collision “block all” and Collision Complexity “project default”, so right now I have no idea what to change collision-wise …)

Thank you very much in advance!