NEW Player Falling Issue

I’m having an issue with the “play from here” that seems quick and easy to re-create. I’m sure it’s something simple I’m missing…

The problem happens when I create a new 1st person map from the UE5.1 version. I test the “play from here” to confirm it works, then I create a box from Modeling Mode with the dimensions 271500 Deep x 206200 Wide x 1 High. After I place the box in the editor, I select
“play from here” again, only this time my character A) starts from the camera view, and B) falls through the floor.

I don’t believe it has anything to do with the normal player start issues like moving the player start above the ground etc. More likely it’s a setting to do with the world dimensions.
Thank you for your help.

Hey there @RennGameDesign! Welcome to the community! So to understand, your first person character is falling through your modeling mode created mesh correct?

Checking the mesh, does it have a simple collision mesh?

Checking the actor’s details, are collisions on and blocking?