My eclipse also makes a weird whistling noise when i shut it down, but apparently that’s normal according to b&o HQ.
Reminds me of an old joke. Guy takes his car to the dealer. It runs rough all the time. Oh, says the guy they all do that. It doesn't start easily when its cold. Oh, they all do that the mechanic says. It gets awful gas mileage. Oh they all do that.
Finally the guy says, don't tell me that! My wife has the identical car, same year and model and it doesn't do that!
Mechanic says, oh, well then, tell her to bring it in and we'll fix it.
Sorry, not making light of your experience, that has to be frustrating as can be and not what one should expect for a product in that price range. That is, about double what a fairly decent car costs.