You are correct that you should check for an object called “Procedural Maze” during Play, but you don’t look for that in the Inspector, look in the Hierarchy. The Inspector is the panel on the top right, while the Hierarchy is the panel on the top left; this shows a list of all the objects in the scene.
What you do next depends on if the object is there. If so, then you just can’t see it, and the camera is probably facing away. Note that polygons in 3D graphics can only be seen from one side, so possibly it is simply facing away. You can reverse the direction a triangle is facing by simply reversing the order of the 3 vertex indexes in the code.
If however the Procedural Maze object hasn’t been created, probably that code is never run, and so you should check that all the relevant scripts are being called.