I also have the same exact noise. It's driving me crazy. I don't even need to be going 40mph for it to rattle. So annoying. Ford wanted $229 to do diagnostics on it yesterday. (2020 Ford Edge SEL 40K miles) it's been happening for years. If I tap it firmly with my hand, it will stop for a little while, then start again.
I've asked ever time I get an oil change and they always just told me they couldn't find anything. Please update me if you find what's wrong with yours.