Character commonly falls through landscape mesh

Hello,
I have used repotologize on one section in my map far away from where it is occuring.
If i smooth or resculpt the zone it does fix it, but after a it is back again. As i’m fully developing the level design this is a really hard setback in my effieciency on not being able to test out the map. Also as soon as this problem occured my “simulated physics” meshes started falling through the ground.