Hello I have exactly the same problem and two mechanics they said the same thing like you , everything is solid but they can’t find where the noisy come from lol .
but there’s a issue we know and I don’t like to have my car doing this noisy .
anyway , one more thing I found that ,is when the weather is sunshine and clear for few days this noisier seems to come up more times then when we have rain and wet days . This is happened with you ?