I had the same issue. Went to local Ford dealer who said it was fan belt. I didn’t see any way that could happen but, sure nuff, when they replaced the belt under warranty all the noise went away. FWIW, mine made lotsa noise when cold but when at normal temperature it only did it at 2,000-2,150 RPM.
A quick check you can do at home is to remove the belt and start the engine. It’s easy to remove and, obviously only run it a very short time.
2018 Forester 3051S (aka Clyde)
2015 Wrangler Toad (aka Bonnie)
At some point during every day you suddenly realize nothing else productive is going to happen the rest of that day. For me, it usually occurs around 9 am.