Losing visuals as I design simple levels

Hi,

I’m very new to UE and I am starting with a tutorial and creating dead simple rooms to get a feel for things. When I add a simple cube to the level (trying to fashion them into walls) everything works fine. It’s when I add a second cube do things become problematic.
The second cube either shows up transparent/invisible or some of the sides are invisible. What am I doing wrong?

I’m using a Gen9 i5 CPU with a 1070Ti GPU with 16GB RAM and an m2 drive.

Any feedback would be very appreciative. Thank you!

Could you please post pictures of you problem so we can have a better sense of what the issue is?

If this is something you have modeled yourself. Make sure the normals of the faces are properly setup and pointing in the correct direction.

I have attached a screenshot of the issue - thank you!

One cube was introduced necessary to flatten it into a wall
Second cube is missing two sides when introduced the flooring
Any ideas why this is occurring?

Thank you!

Try setting the wall with a thickness more than 0, and see if that changes anything.

Unfortunately, it does not give me the option to change ‘wall thickness’ for it is grayed out.

What happens if you start a new default level and repeat the steps?

Have you tried starting a whole new project and repeat the steps to see if that creates the same issue?

I have tried a different project all together with the hopes that would solve the issue - but no change.
Thank you!