It's kind of an interesting result.
Here is how render viewport should look on frame 1:
Here is what happens when I press F12:
It's like I have a second camera (although I don't) somewhere below. What is even weirder is that If I place the camera behind the wall...
it shows everything correctly (example cube is seen):
As you can see, my camera is following an object that is on Bezier curve WHILE being on Bezier curve (right) itself. This animation is working perfectly on rendered viewport but not if I use ctrl+F12. Just the same grey viewpoint.
What could be the issue?