LOL Maybe it's instinct to be very careful , better don't fall into big black holes ! Do the other cats react the same ? Years ago Moritz peed at the fire door in the basement and to keep him away from this door I made a "gate" about 70, 80 cm high out of a cardboard and although he wouldn't have a problem to jump over it he never did because he can't look behind and doesn't know what is there, could be an abyss for example....
Looking at him, I think you're right. It looked like he was afraid of falling into it, or something big jumping out of it! I've never seen such a funny cat in my life!
Somehow, the cat bed in the living room got turned over. I discovered Ambercat investigating about 2 minutes in, and grabbed the camera. It was all I could do to stay conscious and keep the camera steady while I held in the laughs. And yes, I was a jerk and stomped my foot early on.
https://youtu.be/w-srdVqBla8