You might be interested in Dirac large numbers hypothesis, where the mass of the universe depends on the age of the universe. That kind of would be a hint for matter being continually created.
I wish that science channels would stop using the term “fabric of space” because the term is meaningless (or not well defined). What is probably meant when “fabric of space” is mentioned, is the abstract geometrical concept of manifold: en.wikipedia.org/wiki/Manifold
So what we are talking about are coordinates and distances between those coordinates. And I’d consider it unlikely that coordinates and their relations could spawn matter by themselves.