Rattle on front end while driving slow over little bumps ?

The concern could be coming from a steering, suspension or brake system component. It's impossible to guess without a physical inspection of your vehicle and checking it while the problem is occurring.

I have the same problem. 2018 Outback 3.6. It mainly occurs on rough vibrating roads, at slow/medium speeds...not large bumps. It sounds like a bad tie rod but it's not. Can't tell if it's coming from the steering, or the driver's side front wheel or the suspension. It seems to be most apparent during the first 15 min of driving...then it subsides somewhat. Just like many other people that have reported this problem; the dealer service never hears it.