How come all of a sudden I can look through walls in my game?

Recently when I was "developing"lol my game and some others I noticed that if you got close enough to a wall you could look through it?

Is this a bug on ROBLOX's end?

I started a new baseplate and I couldn't see through walls.

Only thing I can assume is I used camera "Scriptable" and then back to "Custom"

Apologize for this not being a semi-coding question but I'm slightly desperate to fix this.