Seagate Ironwolf 4TB, only 40 days powered on, 20000 reallocated sectors, but they are not increasing.
Passes Seagate long self test, 7hour+.
Passed Victoria read/write/test, 2 times.

But it has this weird noise in idle. The moment you copy something to the HDD, this noise goes away. It does it only in idle.
Any idea what's the cause of it?

I added a WAV recording here: https://gofile.io/d/ytc6jU