To be clear, I wouldn't rule out a meteorite, I'm just saying that in order for it to be a meteorite some things need to be understood. The sinkhole hypothesis fits the picture precisely, but requires that someone explain how the top of the cavern got opened in the first place.

In a traditional research setting the next thing we would be doing is coming up with ideas that would rule out a hypothesis in order to give us higher confidence in the ones that remain. To that end, you've added data which doesn't help us rule out either of our hypotheses so it doesn't advance us toward our goal of understanding.

Finding a circular meteor crater on the moon with a cavern underneath it would be useful.

Another useful thing is to look at the sides of the hole. If the material was removed by pushing outwards, the sides will have one shape, if it was removed by 'draining' into the hole in the center they will have another shape. A good experiment you could run on earth to think about that would be a put some sand over a hole and drain it, take that shape. And then to take the same setup, cover the hole lightly, and blow on it with a directed stream of air until you punch through the thin covering on the hole and then take that shape.

If we can figure out the probable way in which the material was removed, that too can inform our hypothesis. I encourage you to keep coming up with ways to figure this out.