My main (and only) camera keeps disabling at startup.

I'm working on a project and I'm quite far into it. I have a singleton gameobject with a bunch of control objects that go through the levels. So far everything works very well. However, in my title screen, I had a second camera, and decided for simplicity to remove it, and simply position the main camera where it was (I was having an issue when going back to the title screen from other levels and I thought this might help.) When the game starts, it goes to a Splash screen (to help load the control objects) and then to the title screen. Now, when I start the game, the camera unchecks itself and turns off. If I manually click it in the inspector, it turns back on, but this is weird, because this camera has been working everywhere and now it doesn't. It is called MainCamera and also has the MainCamera tag, but is not being recognized as the main in scripts. And it unchecks itself. It's so weird, I can't figure out what might be causing it. All parameters are default except that I set the far clipping pane to 100 instead of 1000.

Any ideas?