Without unicode-range, Firefox requests both web fonts in parallel. Chrome/Safari correctly request fallback sequentially after the subset has loaded.
It should wait for the first web font to load to know what code points available in the file and if the fallback is needed.
I have no idea what Chrome is doing here. It renders the div h1 first, when the subset has loaded and then waits for the fallback to render the h1. They should render at the same time—they have the same content.
Why Chrome? Why? 😱